Columbia  ^nibetsiitp  eo  ^ 
in  tbe  Citp  of  iBteto  Porfe        Y 

g)cl)ool  of  Bcntal  anb  0va\  ^urgerp 


leiefetence  l^itirarp 


Digitized  by  the  Internet  Archive 

in  2010  with  funding  from 
Columbia  University  Libraries 


http://www.archive.org/details/practicablerootcOOcran 


A  PRACTrCAP»I.R 


ROOT-CANAL  TECILXIC 


BY 


ARTHUR  BARTON  CRANE,  D.D.S. 


WASHINGTON,    D.C. 


ILLUSTRATED  WITH  48  ENGRAVINGS 


LEA   &  FEBIGER 

PHILADELPHIA    AND    NEW    YORK 


3  0^-;;^, 


Copyright 

LEA  &  FEBIGER 

1920 


this  little  book  is 

dedicatp:d  to 

the  memory  of  the  late 

J.  J.  KINYOUN,  M.D. 

TO  WHOSE   PERSONAL  INTEREST   AND   INSTRUCTION 

THE   AUTHOR   OWES   HIS  DESIRE   FOR  ACCURATE 

SCIENTIFIC  KNOWLEDGE 


PREFACE 


The  object  of  this  little  work  is  to  jHTscnt  in  an  orderly 
manner  a  complete  root-canal  technic  which  is  paving  a  large 
percentage  of  successful  results  in  the  writer's  practice.  Tlie 
facts  and  theories  set  forth  comi)rise  a  digest  of  the  vari- 
ous methods  advocated  by  the  authorities,  modified  and 
supplemented  by  considerable  study  and  some  original 
research.  Much  of  the  matter  included  has  already  been 
made  public  in  papers  and  clinics,  but  it  is  hoped  that  by 
thus  gathering  together  in  a  consecutive  manner  the  pro- 
cedures which  have  been  most  helpful  to  me,  it  may  be  pos- 
sible for  others  by  comparison,  to  clarify  their  own  technic. 

The  subject  will  be  treated  in  the  following  order:  Diag- 
nosis, Asepsis,  Instrumentation  of  the  Canal,  Therapy, 
Bacteriology,  Obliteration  of  the  Canal,  and  Surgery. 

It  will  be  impossible  at  this  time  to  give  due  credit  for  the 
many  suggestions  which  ha\'e  influenced  me  in  arriving  at 
this  technic.  Rhein,  Callahan,  Buckley,  Coolidge,  Ottolengui, 
Black,  Prinz,  (irieves.  Moffit,  McLean,  and  a  host  of  others 
are  the  masters  to  \\h()ni  the  reader  will  owe  any  benefit 
which  may  be  derived  from  a  perusal  of  these  pages. 

Before  proceeding,  let  it  be  understood  that  ihe  writer 
adrocdfrs  the  rct('>iti(ni  af  flic  ininiiituni  uinxber  of  non-vifdJ 
teeth,  (ind  then  onli/  irlicN  these  are  ueeessary  to  preserve  an 
uut)roken  areh,  or  to  afford  retention  of  prosthette  apjdianccs. 

A.  B.  C. 

Washington.  D.  C.    li)2(). 


CONTENTS. 


CHAPTER  I. 

IXTKODUCTION 17 

CHAPTER  II. 

Diagnosis 20 

CHAPTER  III. 

Asepsis 41 

CHAPTER  IV. 
Instrumentation  of  the  Canal  ....       50 

CHAPTER  V. 

Therapy 65 

CHAPTER  VI. 

B.vcteriology SI 

CHAPTER  VII. 
Obliter.vtion  of  the  Canal      ....       89 

CHAPTER  VIII. 

Surgery 104 


IIOOT-CANAL  TECHiNlC. 


CHAPTER  I. 
INTIIODLXTIOX. 

In  view  of  the  divergence  of  opinion  of  the  acknowledged 
leaders  of  dental  thonght,  there  prevails  in  the  average  mind 
an  uncertainty  as  to  the  efficiency  of  any  method  of  dealing 
with  pulpless  teeth.  While  the  medical  profession  in  general 
contemplates  with  scepticism  the  attempts  to  retain  non- 
\ital  teeth  in  situ,  the  natural  repugnance  of  most  patients 
to  submit  to  the  mutilation  of  extraction  places  the  burden 
of  responsibility  squarely  upon  the  dentist. 

The  happy  day  may  come  when  universal  ])roi)hylaxis  will 
I)ractically  eliminate  the  necessity  for  root-canal  work,  but 
the  dentist  of  today  must  be  prepared  to  render  intelligent 
service  to  patients  with  diseases  of  the  dental  i)ul]>.  lie  must 
elect  either  to  extract  at  once  all  teeth  with  exi>osed  or  non- 
vital  pulps  and  absolutely  avoid  devitalization,  or  he  must 
develop  his  root-canal  teehnic  to  a  ])oint  which  will  insmv 
the  patient,  to  a  reasonable  degree,  against  future  extraction. 

The  claim  that  no  infected  tooth  can  be  retained  with 

safety  is  as  absurd  as  the  attempt  to  save  all  teeth.    There 

are  men  in  every  i)art  of  the  country  who  can  present  an 

avalanche  of  roentgenograi)hie  and  ehnieal  e\  idence  ot  bone 

2 


18  INTRODUCTION 

regeneration  in  periapical  areas  previously  infected.  The 
writer  and  others  have  determined  by  occasional  cultural 
tests  through  the  alveolus  that  such  regenerated  areas  are 
commonly  sterile. 

The  question,  then,  is  not  one  of  feasibility  but  ability, 
and  the  reason  dentists  generally  are  not  making  such  teeth 
safe  is  because  they  will  not  devote  the  infinite  attention  to 
detail  which  this  work  demands. 

Whoever  has  followed  the  progress  of  root-canal  technic 
during  the  past  few  years  must  be  gratified  by  the  tendency 
toward  standardization  of  methods  among  the  recognized 
leaders.  In  spite  of  occasional  diatribes  against  the  wisdom 
of  retaining  pulpless  teeth,  the  writer  believes  that  the  prob- 
lem of  a  satisfactory  root-canal  therapy  is  nearing  a  solution. 
Although  the  hopelessness  of  the  reorganization  of  patho- 
logical periapical  areas  can  be  logically  set  forth,  the  fact 
remains  that  actual  cures  are  being  daily  effected.  The  pages 
of  surgical  history  are  illumined  by  the  narration  of  the  over- 
coming of  other  seemingly  insurmountable  difficulties. 

In  1552,  at  the  siege  of  Danvillers  a  shot  passed  through 
the  tent  of  M.  de  Rohan,  and  hit  the  leg  of  one  of  his  retainers. 
One  of  the  most  famous  surgeons  of  all  time  finished  cutting 
it  off,  to  the  wrath  of  his  contemporaries,  refusing  to  use 
either  the  red-hot  irons  or  the  boiling  oil,  then  considered 
indispensable.  Pare  was  ridiculed,  but  the  simple  treatment 
of  wounds  and  the  ligation  of  arteries  which  he  taught,  with 
slight  modifications,  are  fundamental  to  the  surgery  of  today. 

In  1864,  sepsis  following  surgical  operations  was  con- 
sidered inevitable.  In  defiance  of  all  tradition.  Lister  by 
scientific  deduction  evolved  the  true  theory  of  antisepsis. 
The  wise  men  of  the  times  who  prided  themselves  upon 
the  number  of  old  blood  stains  on  their  operating  coats 


ISTIiODlCTIOS  19 

(•nii(l('iiiiu'(l  his  work  as  daiipTous  ])r()cc(]urc,  but  to  the 
^M-cat  uii(k'rlyin<i;  tnitli  ol"  liis  theories  is  (hie  the  aseptic 
surj^ery  of  tcxhiy. 

In  1915,  in  France,  a  wouiuU-d  soldier  is  l)rou^dit  into  a 
h()S])ital.  A  wound  in  tlie  Ici^,  su])i)uratinf;,  contused,  full 
of  hits  of  shrai)nel,  dirt  and  j)ieces  of  clothing',  has  caused 
an  alarming  ele\ation  of  tenij)erature.  Lot^ical  surgical 
tradition  would  call  for  the  amputation  of  this  leg,  but 
thanks  to  the  scientific  bravery  of  Carrel,  in  a  few  weeks 
this  man  is  back  on  the  firing  line. 

Before  Pare,  the  treatment  of  gunshot  wounds  without 
the  use  of  hot  oil  and  hot  iron  was  impossible;  before  Lister, 
deliberate  surgical  operations  without  subsequent  sepsis 
intervening  were  impossible;  before  Carrel,  the  closure  of  a 
suppurating  wound  in  four  days  was  impossible. 

Perhaps  in  dentistry,  also,  the  seemingly  impossible  may 
be  accomplished.  The  treatment  of  periapical  disease  may 
yet  be  placed  upon  such  a  scientific  basis  that  none  will 
question  its  expedience.  Great  men  like  Callahan  may  go  to 
their  gra^'es  with  the  condemnation  and  destructive  criti- 
cism of  the  wise  men  ringing  in  their  ears,  but  this  problem 
will  never  be  solved  by  the  man  who  throws  up  his  hands. 

Vincent,  of  Carrel's  grou]),  found  that  only  about  30  per 
cent,  of  surgically  aseptic  wounds  were  bacteriologically 
asei)tic.  Yet  thousands  of  soldiers  who  owe  their  li\es  to 
Carrel  and  Dakin  would  laugh  to  scorn  the  critic  who  con- 
demned their  treatment  on  that  account.  So  while  the 
hypercritical  pro-extractionists  continue  to  prove  that  it  is 
imi)ossil)le  to  render  an  infected  tooth  and  its  environs 
bacterio!ogi(all\'  ase]>tic.  perhai)s  we,  too,  may  dejxMid  upon 
the  natural  resistant  forces  to  exert  the  same  influence 
in  the  alveolus  which  contributes  to  the  cure  of  infections 
elsewhere  in  the  body. 


CHAPTER  II. 
DIAGNOSIS. 

The  foundation  principle  of  a  practicable  root-canal 
technic  is  accurate  diagnosis.  Diagnosis  is  a  scientific 
determination  or  discrimination  of  diseases  by  their  symp- 
toms. It  calls  for  a  knowledge  of  cause  and  effect  acquired 
only  by  a  wide  clinical  observation.  It  is  the  embodiment 
of  experience.  Without  a  correct  perception  of  conditions 
to  be  met  any  treatment  becomes  empirical. 

In  the  management  of  root-canals  a  careful  diagnosis 
based  upon  methodical  examination  should  precede  any 
effort  at  treatment.  Thereby  much  time  and  useless  effort 
may  be  saved,  and  respect  for  the  prognosis  of  the  dentist 
increased. 

The  diagnostic  procedure  should  begin  with  a  thorough 
physical  examination.  If  this  is  properly  conducted  it  will 
not  only  indicate  suspicious  teeth,  but  in  many  instances 
will  classify  those  which  may  be  expected  to  respond  favor- 
ably to  therapeutics,  those  whose  only  hope  lies  in  surgery, 
and  those  which  must  be  condemned  to  extraction. 

The  following  conditions  if  found  indicate  the  advis- 
ability of  further  investigation: 

Color. — A  tooth  whose  shade  is  not  in  harmony  with  its 
fellows  is  probably  the  seat  of  a  pulp  lesion. 

Translucence. — ^This  is  commonly  called  the  live-tooth 
appearance.    When  it  is  absent  the  pulp  is  probably  dead. 


TESriXd   THE  TKKTII  21 

A  small  mouth  lam])  held  liMj,niall\  w  ill  he  <»f  j^rcat  assistance 
in  (Ictorinininj,'  this  j)()int. 

Large  Cavities. — These  should  he  carefully  excavated  and 
tested  with  a  sliarj)  e\]>lorer  to  determine  ])roxinnty  to 
the  ])ul|)  (  lianihcr. 

Large  Fillings  These  are  always  suspicious,  and  should 
nex'cr  he  i)assed  without  thoroui^h  tests. 

Gold  Crowns. — Teeth  under  gold  crowns  are  also  always 
susi)ieious.  The  wonder  is  not  that  so  many  pulps  die  in 
such  teeth,  hut  that  any  survive.  The  reason  for  this  is  that 
the  freshly  denuded  dentin  is  left  exposed  to  the  fluids  of 
the  mouth  until  the  crown  or  inlay  is  set.  Infection  invades 
the  dentinal  tuhuli,  and  is  sealed  in  to  continue  its  activity 
until  at  last  the  pulp  becomes  infected.  As  a  precautionary 
measure  a  mild  antiseptic  should  be  sealed  in  contact  with 
exposed  dentin  before  the  patient  is  dismissed.  Cement 
should  be  used  in  cavities  and  aluminum  shells  for  crowns. 
A  cement  of  eugenol  and  oxid  of  zinc  is  excellent  for  this 
purpose. 

Post  Crowns. — With  rare  exceptions  these  are  ])laccd  on 
puli)less  teeth. 

Crownless  Teeth. — These  sometimes  contain  vital  pulps, 
but  unless  treated  prior  to  restoration  will  surely  cause 
after-trouble. 


TESTING   THE   TEETH   BY   MEANS    OF     THE   ELECTRIC 
CURRENT. 

Having  marked  all  teeth  which  are  suspicious  by  the  fore- 
going tests,  they  should  be  further  checked  by  means  of 
the  electric  current.    Either  the  Faradic  or  galvanic  current 


22  DIAGNOSIS 

may  be  used,  the  only  requirement  being  some  method  of 
controlling  the  dosage.  The  high-frequency  current  is  also 
useful  in  this  connection,  but  it  is  more  difficult  to  concen- 
trate this  current  upon  given  areas  of  the  tooth  crown,  and 
thus  a  faulty  diagnosis  may  result.  "With  any  of  the  stand- 
ard galvanic  switchboards,  such  as  are  used  for  electrolytic 
medication,  the  test  is  made  as  follows: 

A  section  of  a  broken  broach  is  fitted  into  the  needle- 
holder  and  attached  to  the  positive  wire.  The  sponge 
electrode  is  soaked  with  salt  water  and  held  by  the  patient 
in  the  palm  of  the  hand.  The  tip  of  the  broach  is  wrapped 
with  cotton  fibers,  and  this  also  is  moistened  with  salt  water. 
Several  teeth  which  are  unquestionably  vital  are  now  tested, 
and  the  tolerant  dosage  noted.  With  this  as  a  control  the 
suspicious  teeth  are  tested.  Machat  warns  against  touching 
the  electrode  to  metal  fillings  or  crowns,  but  as  the  resistance 
of  sound  enamel  varies  so  much  in  individual  teeth,  it  is 
generally  satisfactory  to  apply  the  electrode  to  a  filling  or 
crown  where  the  metal  does  not  come  into  contact  with 
the  soft  tissues,  especially  where  corresponding  fillings  or 
'crowns  on  teeth  of  known  vitality  can  be  had  as  controls. 

It  should  be  borne  in  mind  that  more  current  is  required 
to  penetrate  enamel  than  metallic  fillings,  also  that  crowns 
and  inlays  have  an  intermediary  of  more  or  less  non-con- 
ductive cement,  which  causes  these  teeth  to  respond  only 
to  an  increased  dosage.  Recession  of  the  pulp  or  thick 
deposits  of  secondary  dentin  in  the  pulp  chamber  must  also 
be  taken  into  consideration.  When  the  canal  is  filled  with 
the  liquid  products  of  decomposition,  the  tooth  is  often  quite 
as  sensitive  to  electricity  as  if  the  pulp  were  vital,  and  where 
hyperemia  of  the  pulp  exists,  the  tooth  will  often  be  more 
sensitive  than  the  control.    For  teeth  in  which  the  electro- 


I 


PEIiCUSSlOM  23 

(liaiiiiostic   test    is   iiicoiiclusiNC   llic   (ild-tasliioiicd   tlicrinal 
tests  will  often  he  of  assistance  in  clearing;  tlie  diaf^nosis. 

IlaNiiiLi;  i)y  the  forc^oin^  tests  exclndcd  llic  teeth  of 
iin(iuestional)le  \itality,  tlie  next  ste])  is  a  clinical  examina- 
tion of  the  periapical  region.  Careful  search  sliould  be  made 
for  fistuli?  or  scars  where  these  have  healed.  The  discovery 
of  such  will  suggest  more  or  less  destruction  of  periapical 
tissue,  hut  there  will  often  be  as  much  or  more  disorganiza- 
tion where  this  evidence  does  not  exist. 


PERCUSSION. 

The  degree  to  which  the  apical  attachments  of  the  tooth 
ha\e  been  destroyed  may  be  judged  by  percussion.  The 
so-called  "  didl  note"  of  the  older  practitioners  requires  a 
trained  ear,  but  has  a  definite  value.  The  percussion  test 
of  Talbot  is  of  more  universal  utility.  This  is  accom- 
plished by  placing  a  finger  of  the  left  hand  over  the  apex  of 
the  suspected  root  and  striking  the  cusps  of  the  tooth  with 
a  heavy  instrument  at  different  angles.  If  the  bone  has 
undergone  destruction  the  ^■ibrations  will  be  transmitted 
through  the  root  to  the  finger.  This  test  is  of  greater  value 
on  anterior  teeth  than  on  molars;  where  ])yorrhea  exists  it 
is  utterly  confusing. 

To  ascertain  the  extent  to  which  the  houy  plate  of  the 
alveolar  ]>r()cess  has  been  destroyed,  take  a  small  hard 
])ledget  of  cotton  in  the  cotton  ])liers,  and  i)ress  hard  on  the 
mucous  nunihrani-  oN'erlying  the  root  apex.  The  tissues  will 
sink  into  such  an  oi)ening,  and  slowly  return  when  ])ressiu'e 
is  i-cni(i\('(l.  The  ai)])earance  is  much  the  same  as  ])itting 
of  the  skin  by  ])ressin'e  in  edema. 

\Vhcne\cr  the  clinical  tests  classify  any  tooth  as  suspicious, 


24  DIAGNOSIS 

the  patient  should  be  carefully  questioned  as  to  its  history. 
Some  patients  have  extremely  good  memories,  and  almost 
all  can  remember  a  prolonged  toothache  or  the  swelling  of 
the  face  in  the  region  of  the  tooth  in  question. 

THE  X-RAY  AS  AN  AID  IN  DIAGNOSIS. 

With  the  data  now  in  hand  all  teeth  recorded  as  non-vital 
or  suspicious  should  be  radiographed  to  complete  the  diag- 
nosis. Correct  interpretation  of  dental  radiographs  cannot 
be  made  in  the  absence  of  good  clinical  data,  and  this  point 
cannot  be  made  too  strong.  Neither  can  radiographs  be 
properly  read  by  one  deficient  in  the  knowledge  of  normal 
dental  anatomy.  The  density  of  the  film,  the  angle  from 
which  the  exposure  has  been  made,  the  density  of  super- 
imposed structures,  and  the  contiguity  of  other  anatomical 
formations  must  all  be  taken  into  consideration. 

In  reading  a  dental  .r-ray  film,  the  teeth  known  to  be  normal 
should  first  be  studied  (Fig.  1).  The  use  of  a  good  reading- 
glass,  or  dentiscope,  will  be  of  great  help.  It  will  be  noted 
in  the  case  of  a  normal  tooth  that  the  pericementum  can  be 
traced  around  the  root  as  a  continuous  radiolucent  line. 
Adjacent  to  and  surrounding  this  will  be  seen  the  lamina 
dura  or  radiopaque  line.  It  will  also  be  noted  that  the 
trabeculse  of  bone  about  the  apex  are  homogeneous  with  the 
bone  which  lies  adjoining. 

Infection  is  microscopical,  and  cannot  be  radiographed. 
What  we  look  for  in  the  film  is  not  infection,  but  the  results 
of  infection.  Thus  it  may  happen  that  a  tooth  recently 
infected  or  one  long  the  habitat  of  organisms  of  low  virulence 
may  present  a  radiographic  record  in  no  way  differing  from 
the  normal  (Fig.  2) .    Again,  in  the  entire  absence  of  infection 


TlfK  X-h'AY   AS  A\  AID  I.\   h/ACXOSIS  2."» 

there  may  hv  a  raretViii<f  j)r()cess  in  the  adjacent  bone  suffi- 
cient to  cause  a  most  decided  radiolucent  area.    Tliis  latter 


Fig.  1. — The  cuspid  is  iioniial.  Note  the  contiuuuus  line  of  the  peri- 
cementum and  the  lamina  dura.  Also  the  homogeneity  of  the  surroimding 
trabecula;  of  bone.     Compare  with  apical  regions  of  lateral  and  first  bicuspid. 

picture  is  caused  by  overstimulation,  as  in  traumatic  occlusion 
(Fig.  3)  or  orthodontic  procedure,  and  may  also  be  observed 
about  the  forming  roots  of  adolescence  (P'ig.  4).     Bearing 


Fig.  2. — Infected  cuspid,  with  no  radi<iy.r;ii'liic  evidence  of  periapical 
disturbance.     Streptococcus. 


these  ])oints  in  niiiid,  the  sus])icious  tooth  should  l)e  examined 
to  see  in  w  hat  inanncr  it  dillVrs  from  the  normal. 


26 


DIAGNOSIS 


The  first  thing  to  look  for  is  a  thickening  or  break  in  the 
Hne  of  the  pericementum  at  the  apex  of  the  root.  Next 
the  bone  about  the  apex  should  be   examined  for  radio- 


Fio.  3. 


-Radiolucent  area  about  apex  of  second  bicuspid,  caused  by 
traumatic  occlusion.     Pulp  vital  and  normal. 


parency  or  radiolucency,  and  the  presence  or  absence  of  the 
lamina  dura  noted;  then  the  periphery  of  the  apex  should 
be  studied  for  evidence  of  roughness.  When  any  or  all  of 
these  signs  are  recorded  in  the  radiograph  of  a  tooth  which 


Fig.  4. 


-Note  radiolucent  area  about  root  apices  of  first  molar. 
Pulp  normal. 


the  clinical  examination  has  shown  to  be  non-vital,  we  may 
safely  conclude  that  the  tooth  is  infected,  and  that  we  are 
dealing  with  periapical  disease.    Where  all  of  these  signs  are 


CLASSIFICATION  OF  I'KUIM'K'M.   DISEASE  27 

ahst'iit,  and  the  i)uli)  is  known  to  be  contauiiniitcd  or  dead, 
the  infection,  if  present,  while  confined  to  the  root-canal  and 
dentin,  i>  still  a  constant  menace  to  the  periapical  tissues. 

At  tliis])oint  we  are  enabled  to  make  a  differential  diagnosis 
and  the  tooth  in  ([Uestion  nuist  he  i)lace(l  in  one  of  the 
following  classes: 

A.  Pulp  normal. 

B.  Pulp  ex])osed,  hut  not  infected  (rare). 
(\  Pul])  ex])osed  and  infected. 

I).  Pulp  undergoing  decomposition. 

1''.   Pul])  non-vital,  but  no  ])eriai)ical  disturbance. 

P.  Pulp  non-vital,  with  periapical  disease. 

CLASSIFICATION  OF  PERIAPICAL  DISEASE. 

A  com})arative  study  of  radiographs  with  the  actual  con- 
dition of  the  tissues,  as  disclosed  by  numerous  root-resections, 
has  led  me  to  the  conclusion  that  in  periapical  disease  we  are 
dealing  with  three  distinct  conditions,  which  may  in  most 
cases  be  differentiated  in  the  film.  For  the  sake  of  con- 
venience I  have  differentiated  these  conditions  as  follows 
(Fig.  5): 

Class  I.  Circumscribed  radiolucent  areas.  (Primary 
granuloma). 

Class  II.  Diffuse  radiolucent  areas.  (Advanced  granu- 
loma.) 

Class  III.  Circumscribed  radioparent  areas.  (Dental 
cyst.)    (Figs.  (■)  and  7). 

The  outstanding  characteristics  of  these  three  classes  are 
as  follows: 

Class  I  (Fig.  G,  .1) :  Circumscribed  Radiolucent  Areas. 
— At  first  glance  this  nui\'  disclose  no  abnorinalit\'  of   the 


28 


DIAGNOSIS 


Class  I.  Class  11.         Class  III. 

Fig.  5. — I,  circumscribed  radiolucent  area  (granuloma) ;  II,  diffuse  radiolucent 

area  (granuloma) ;  III,  circumscribed  radio  parent  area  (dental  cyst) . 


Class  I. 


Class  II. 


Periapical  ilisoase,  Cla.-^s  1/ 
circuniscril)C(l  radioluccnt 
about  second  bicuspid. 

C 


Note 
area 


Periapical  disease,  Class  II.  Note 
diffuse  radiolucent  area  about  second 
bicuspid. 

D 


Periapical  diesase,  Class  III.  Xote 
circumscribed  radioparent  areas,  sur- 
rounded by  radiopaciue  line.  These 
cysts  were  sterile. 


Periapical  disease.  Class  I,  on 
mesial  root;  Class  III,  on  distal 
root,  lower  first  molar. 


Periapical    disease.   Class    II,  on  Periapical  disease.  Class  I,  on  left 

cuspid;     Class   III,   on  second   bi-       central;  Class   II,  on   right    centnU; 
cuspid.  Class  III,  on  right  lateral. 

Fia.  7. 


30  DIAGNOSIS 

periapical  tissues,  except  a  slight  thickening  in  the  periapical 
pericementum,  or  it  may  present  any  extent  of  rarefying 
osteitis.  There  may  or  may  not  be  evidence  of  previous 
attempt  at  root-canal  filling.  This  condition,  in  the  absence 
of  such  evidence,  is  too  frequently  passed  with  a  glance, 
when  a  more  prolonged  study  will  reveal  an  absence  of  the 
apical  lamina  dura  and  an  indefinitely  circumscribed  area,  to 
a  varying  degree  more  radiolucent  than  the  surrounding 
bone.  To  fall  into  Class  I,  however,  no  matter  what  the 
degree  of  periapical  disturbance,  the  area  must  be  circum- 
scribed, with  the  radiolucent  area  blending  gradually  into 
the  normal  bone. 

In  cutting  down  upon  these  areas  the  alveolar  plate  will 
generally  be  found  to  be  intact,  but  behind  this  a  mass  of 
soft  granulations  will  be  found  investing  the  root  apex.  This 
class  represents  the  primary  results  of  infection,  and  the 
affected  area  is  circumscribed,  because  the  vital  forces,  while 
being  slowly  overcome  by  the  invading  organisms,  are,  as 
it  were,  making  an  orderly  retreat.  It  often  happens  at  this 
stage  that  proper  root-canal  treatment  so  attenuates  the 
invading  host  that  the  balance  of  power  passes  to  the  tissues, 
and  a  cure  results. 

For  the  better  understanding  of  the  statement  just  made 
the  microscopical  picture  of  primary  granuloma  must  be 
studied  (Fig.  8) .  Under  the  low  power  may  be  seen  a  fibrous 
capsule  surrounding  a  cellular  central  portion.  Under  high 
power  the  capsule  is  seen  to  be  composed  of  dense  white 
fibers  of  connective  tissue,  with  numerous  vessels  and  capil- 
laries. There  is  a  scattering  of  wandering  tissue  cells  and 
fibroblasts.  The  central  portion  is  composed  of  plasma  cells, 
fibroblasts,  lymphocytes,  and  leukocytes,  lying  in  an  indefi- 
nite stroma  of  embryonic  connective  tissue.    Careful  exami- 


ri..\ssiFf(\\ri().\  OF  I'Kin M'icM.  dise.xsk 


?A 


nation  will  n-vcal  tlic  (•:i])illan  l()(ti)s  often  lined  with  a  single 
layer  of  eiKlotlicliuin.  It  is  from  these  delieate  vessels  that 
the  iiitlainniatory  eells  })rol)ai)ly  have  tlieir  distribution. 
Such  a  ])ath()l()gical  arrangement  is  strongly  indicative  of 
nature's  effort  to  wall  olV  the  irritant. 


Fig.  8. — Photoniicrograiih  of  adxamcd  granuloma,  a,  degenerative  area; 
h,  leukocj-tes  and  bacteria;  c,  fil)rinoiLs  layer;  d,  granulation  tissue;  dd,  capii- 
larj-  loop;  c,  pericementum. 


rL.\ss  11  (Fig.  G,  B):  Diffuse  Kadioucknt  Area. — 
This  class  shows  in  the  film  an  irregularity  of  the  radiolucent 
area,  which  ina\'  \ary  from  a  simple  hreak  in  limitation  to 
an  entire  loss  of  form.  .\s  in  Class  1,  the  limitations  of  the 
abnormal  area  are  ])oorly  defined,  and  it  is  imjiossible  to 
determine  the  borderline  between  normal  and  rarefied  bone, 


32  DIAGNOSIS 

so  gradually  does  one  blend  into  the  other.  The  irregu- 
larity of  general  outline  is  caused  by  ramifications  of 
inflammatory  tissue  which  extend  from  the  central  mass 
into  the  surrounding  bone.  Wherever  this  abnormal  tissue 
comes  in  contact  with  bone  or  cementum  disintegration  of 
the  hard  tissues  takes  place.  The  cementum  becomes 
roughened  and  the  bone  becomes  softened.  This  condition 
represents  the  absence  of  the  reparative  effort  exhibited 
in  Class  I  cases,  and  follows  neglect  or  improper  treat- 
ment of  the  primary  infection.  While  it  sometimes  happens 
that  Class  II  cases  respond  to  treatment,  the  destructive 
process  has  reached  so  advanced  a  stage  that  it  is  seldom 
that  teeth  in  this  condition  are  restored  to  health,  except 
by  root  resection.  Indeed,  the  infection  in  this  class  of 
cases  is  rarely  eliminated  even  by  extraction  unless  exten- 
sive curettement  is  performed.  Under  the  microscope  the 
advanced  granuloma  shows  areas  of  degeneration  in  the 
central  mass,  which  appear  as  lumina  containing  fluid  or 
cheesy  matter. 

Class  III  (Fig.  6,  C):  Circumscribed  Radioparent 
Areas. — In  this  class  the  film  shows  an  intensely  dark  cir- 
cumscribed area  surrounding  the  root  apex.  This  dark  area  is 
outlined  by  a  dense  white  line,  which  definitely  separates 
radioparent  from  normal  bone.  Such  a  picture  is  always 
indicative  of  a  dental  cyst.  In  cutting  down  on  these  cases  a 
definite  cyst  wall  will  be  found  attached  to  the  root-end.  By 
careful  dissection  this  may  be  freed  from  its  bony  capsule  and 
by  resecting  the  root  just  below  its  attachment  the  whole  cyst 
may  be  removed  en  masse.  The  limiting  wall  of  bone,  which 
shows  in  the  radiograph  as  a  dense  white  line,  will  be  found 
to  be  smooth  and  hard.  If  the  cyst  be  opened  it  will  be  found 
to  contain  a  straw-colored  fluid.    Cysts  are  an  expression  of 


CLASSIFICATIUX   OF   I'F.ni M'lC .\  L    DISEASE  WW 

nature's  effort  to  protect  tlie  or<^aiiisiM  from  tlie  haiiefiil 
effects  of  certain  noxious  irritants.  Microsco])ically  the  cyst 
wall  will  l)c  seen  to  l)c  formed  of  connectix'e-tissue  fibers 
lined  with  cpitlicliid  cells.  In  Lrrainiloniata  which  dcx'elo]) 
necrotic  areas,  epithelial  strands  may  often  he  seen  surround- 
ing the  necrotic  area.  Thus  certain  Class  I  eases  go  on  to 
cyst  formation,  while,  on  the  othei-  hand,  the  frequency  with 
whicli  radicular  cysts  api)ear  as  a  late  se(|uel  to  de\italization 
of  the  ])ulp  from  traumatism,  suggests  the  possibility  that 
in  some  instances  these  growths  are  not  of  infectious  origin. 
Whether  infected  or  not,  cases  of  completed  cyst  formation 
as  included  in  Class  III  are  probably  never  eradicated  by 
treatment  through  the  canal.  The  cyst  wall  must  lie  entirely 
destroyed  or  the  cyst  will  reform. 


FiG.'O. — Chronic  abscess  with  fistula;.     Note  alxsence  of  periapical 
disturbance. 

A  ty])e  of  ])eria})ical  disease  not  mentioned  above  which  is 
frequently  encomitered  is  aKeolar  abscess,  either  acute  or 
chronic,  with  tendenc\-  to  Hstula  formation.  This  may 
present  a  radiograi)hic  record  identical  with  any  of  the  fore- 
going classes,  or  in  extremely  rai)id  establishment  of  drainage 
may  produce  so  little  periapical  destruction  as  to  escape 
3 


34 


DIAGNOSIS 


detection  in  the  film  (Fig.  9.)  Where  an  abscess  exists  in 
conjunction  with  Classes  I,  II,  or  III  of  periapical  disease, 
it  is  usually  caused  by  the  secondary  invasion  of  Staphylo- 
cocci pyogenes.  When  acute  alveolar  abscess  does  not 
record  proliferative  tissue  changes  in  the  film,  it  is  likely  to 
be  the  result  of  infection  by  the  Staphylococcus  pyogenes, 
the  Streptococcus  hemolyticus,  or  both. 

A  further  important  point  for  study  in  the  radiograph  is 
the  condition  of  the  root  apex,  and  this  is  obviously  of  greater 
prognostic  value  than  the  condition  of  the  surrounding  bone. 
If  the  cementum  is  exposed  and  roughened  it  is  certain  that 
there  is  no  present  treatment  by  which  this  infected  necrotic 
tissue  can  be  restored  to  life,  to  say  nothing  of  health. 


Fig.  10. — -Lower  cells  of  antrum. 
Trace  pericementum  about  apex  of 
lingual  root  of  molar. 


Fig.  11. — The  nostrils  superimposed 
upon  root  apices  of  centrals. 


ANATOMICAL  CONSIDERATIONS. 

Anatomical  points  which  seem  to  cause  the  most  confusion 
are  the  lower  cells  of  the  antrum  (Fig.  10),  the  nostrils  (Fig. 
11),  and  the  anterior  palatine  foramen  (Fig.  12)  in  films  of 


AAA  TOMICAL  COS  SI  DERATIONS 


35 


tlic  upper  tcclli,  nnd  llic  mental  foramen  (Fif^.  V^)  in  films 
dl'  tlic  Idwcf.  'The  (|iiesti(iii  of  infected  areas  in  these  re,i:ions 
can   lie  (piicklv  (K'lci'niiiicd  hy  ti'acin^^  the  line  of  liie  jx'ri- 


A 


Fk;.  12. — .1,  ahtciior  palatine  foramen;  B,  taken  from   furtlier  to  the  right 
than  .-1  clarifies  the  diagnosis. 


I'lo.  13. — Mental  foramen.     Note  termination  of  inferior  dental  canal. 


eeinentnni  around  tlie  root  \\\n'\.  If  tliis  is  intact  llic  dark 
radiolucent  area  cannot  l)e  caused  hy  infection  from  tlie 
root-canal.  Occasionally  it  is  necessary  to  get  an  exposure 
from  a  dilTerent  ande  to  verify  the  rcadinc:  (Fi.t;.  12). 


36 


DIAGNOSIS 


CASES  IN  WHICH  TREATMENT  THROUGH  THE  ROOT- 
CANAL  IS  CONTRA-INDICATED. 

It  may  as  well  be  acknowledged  that  there  are  many 
infected  teeth  which  cannot  be  saved,  but  a  selection  of  risks, 
through  careful  diagnosis,  makes  a  favorable  prognosis  rea- 
sonably safe  in  many  instances.  For  the  sake  of  convenience, 
infected  teeth  which  are  rarely  benefited  by  treatment 
through  the  canal  may  be  classified  in  three  groups  as  follows 
(Fig.  14): 


Group  I  Group  II  Group  III 

Fig.  14. — Types  unfavorable  for  canal  medication.  I,  too  much  dead 
apical  cementum;  II,  too  much  dead  alveolar  cementum  (pyorrhea);  III, 
canal  opening  within  the  antrum. 

Group  I. — Teeth  having  considerable  dead  apical  cemen- 
tum. 

Group  II. — Teeth  having  considerable  dead  alveolar 
cementum. 

Group  III. — Teeth  having  their  apical  opening  within  the 
maxillary  sinus. 

Group  I  (Fig.  15). — A  careful  consideration  of  these  three 
groups  may  have  a  tendency  to  prevent  many  unsuccess- 
ful attempts  at  tooth  treatment.  Recalling  the  classification 
of  periapical  disease  previously  referred  to,  it  will  be  realized 
that  most  cases  of  Class  II  and  all  cases  of  Class  III  have  so 
much  denuded  and  therefore  dead  apical  cementum  that 


TREATMENT   TUh'ordll   THE  ROOT-CAXAL 


V,t 


they  must  be  iiicludrd  in  (irouj)  I.  After  one  has  extracted 
a  miinher  of  siicli  teetli  and  curetted  the  ])eriai)i<al  l)()ne,  or 
better  still,  has  cut  down  upon  thcin  for  root-resections,  it 
requires  eonsiderahk'  faith  in  the  ])()teney  of  antisei)tios  to 
believe  that  this  infected  fiehl,  full  of  dead  and  dyinj;  tissue, 
with  the  ex])osed  ai)ical  cenieutum,  which  can  neither  be 
sterilized  nor  insulated,  actinjx  as  a  continuous  irritant,  can 
ever  be  restored  to  health  b\'  treatment  throuj^h  the  canal. 


Fig.  15. — Group  I,  too  nmcli  dead  apical  cementum. 


Fici.  16. — Group_II,  too  niuch  dead  alveolar  cementum. 


Group  II  (Fig.  10).— Teeth  having  considerable  dead 
alveolar  cementum  are  those  ])ul|)less  teeth  which  have 
])yorrhea  to  the  extent  of  i)ocket  formation.  In  such  cases 
there  is  generally  a  j)athway  of  drainage  establishetl  from  the 
periapical  area  to  the  gingival  margin,  which  can  often  be 


38  DIAGNOSIS 

traced  out  in  the  radiograph.  Attempts  to  sterihze  such 
teeth  invite  failure,  as  constant  reinfection  will  ensue. 

Group  III. — ^Teeth  having  their  apical  opening  within 
the  maxillary  sinus  when  affected  with  periapical  disease  are 
of  unfavorable  prognosis,  because  in  most  cases  of  this  char- 
acter it  is  probable  that  an  infected  granulation  tissue  has 
been  substituted  about  the  root  apex  for  the  normal  lining 
membrane  of  the  antrum,  and  reinfection  is  almost  certain 
to  occur. 

The  dental  a^-ray  film  is  an  unreliable  guide  as  to  the  rela- 
tion of  the  tooth  root  and  the  maxillary  sinus.  Fortunately 
we  have  a  means  of  physical  diagnosis  which  is  conclusive. 
When  the  pathfinder  is  passed  through  the  apical  foramen 
in  certain  upper  bicuspids  and  molars,  there  is  a  twinge  of 
pain,  after  which  the  instrument  moves  upward  without 
resistance  or  pain.  This  is  an  indication  that  the  antrum  of 
Highmore  has  been  invaded. 

Artificial  perforation  of  the  lateral  cementum  may  usually 
be  discovered  by  the  tendency  to  hemorrhage,  and  persistent 
seepage.  The  patient  can  generally  localize  the  pain  as  being 
in  the  gum  when  an  instrument  is  passed  through  the  perfora- 
tion. Diagnostic  wires  are  often  helpful,  but  if  the  puncture 
is  lingual,  or  labiobuccal,  the  radiograph  is  unreliable.  If 
the  false  opening  is  accessible,  it  may  at  times  be  filled  suc- 
cessfully. Occasionally  a  puncture  near  the  apex  may  be  so 
capped  with  gutta-percha  that  it  is  not  a  source  of  irritation. 
More  frequently,  however,  teeth  so  mutilated  become  lame, 
and  must  be  extracted. 

SUMMAEY. 

To  summarize,  then,  we  are  confronted  by  the  prospect 
that  the  only  teeth  which  offer  opportunity  for  favorable 


THE.  1  TM l-:.\  7'    77/ /.v > I  (ill    'I'll /■'    h'OOT-CA XA  L 


30 


])r()^Mi()si.s  in  root-canal  treatment  arc  those  with  (lass  1 
])criaj)i('al  disease,  of  limited  deforce,  and  those  in  which  the 
])eriai)iciil  coiiditions  arc  still  normal. 

It  often  happens,  after  the  most  exhanstive  cIVorts  at  diag- 
nosis, that  there  remains  an  nncertainty  as  to  the  necessity 
for  interference  with  certain  teeth.  For  the  most  ])art  these 
are  teeth  with  ])artially  filled  canals  and  no  evidence  of  \wy\- 


i 


Fig.  17. — Coricll's  trocar  and  cannula. 


apical  distiirl)ance,  or  well-filled  canals  recently  treated, 
which  still  show  radiolucent  bone  areas  about  the  root  apex, 
I'litil  some  method  is  aiKanccd  of  dctcrmininii'  when  the 
ai)ical  foramina  have  been  sealed  by  a  new  jj;rowth  of  cemen- 
tum,  any  tooth  with  an  incomplete  canal  filling  should  be 
considered  a  source  of  danger,  no  matter  what  the  ])eriapical 
condition,    ^^'e  nuist  constantK'  bear  in  mind  that  the  radio- 


40  DIAGNOSIS 

graph  is  but  a  record  of  macroscopical  conditions,  while 
infection  is  the  result  of  a  microscopical  invasion. 

An  instrument  has  recently  been  devised  by  Coriell  (Fig. 
17),  of  Baltimore,  which  is  of  the  greatest  value  in  deciding 
upon  the  necessity  for  treatment  in  these  extremely  doubtful 
cases.  This  consists  of  a  trocar  drill  and  cannula,  so  con- 
structed that  it  can  be  used  in  the  right  angle  hand-piece  of 
the  dental  engine.  By  means  of  this  instrument  a  hole  may 
be  made  through  the  alveolus  to  the  root  apex,  after  which 
the  drill  may  be  withdrawn,  leaving  the  cannula  in  place. 
Through  this  an  uncontaminated  culture  may  be  taken,  which 
will  definitely  determine  the  bacteriological  condition  of  the 
periapical  tissues.  The  operation  can  be  performed  with 
local  anesthesia  in  a  few  minutes,  but  the  utmost  aseptic 
precaution  is  necessary  to  make  the  result  of  value. 


CIIArTER  111. 

ASEPSIS. 

TiiK  object  of  asoi)sis  is  to  reduce  to  a  iiiiniiiiuiii  the  anioiiiit 
of  infection  wliicli  may  he  introchiced  into  the  fiehl  by  an 
operation.  Any  ase])tic  technic  gives  at  best  only  rehitively 
sterile  results.  The  most  careful  surgeon  cannot  incise  the 
skin  without  some  contamination.  Fortunately,  most  of 
the  organisms  thus  introduced  are  non-pathogenic,  and  the 
natural  resistance  of  the  tissues  defends  them  from  the  bane- 
ful effects  of  bacteria,  if  introduced  only  in  limited  amount. 
Natural  resistance  is  dependent  upon  the  elements  of  the 
blood  stream,  which  is  entirely  absent  from  the  dentin  of  a 
])ulpless  tooth.  Thus  the  difficulty  of  an  aseptic  root-canal 
technic  is  augmented  at  the  start.  Add  to  this  the  natural 
(HsiiK  liuatioii  of  the  patient  to  submit  to  the  inconvenience 
of  sterile  wrai)i)ings  for  the  head  and  face,  as  well  as  his 
average  inability  to  i)ay  for  the  time  thus  consumed  in  many 
sittings,  and  the  difficulty  increases.  Furthermore,  consider 
that  the  use  of  rubber  gloves  robs  the  dentist  of  that  delicate 
sense  of  touch  so  necessary  to  the  ])r()i)er  ])erformance  of 
root-canal  work,  and  that  even  with  the  greatest  care  the 
hands  will  usually  ha\t'  to  come  into  contact  with  some 
unsterile  object,  and  the  achievement  of  an  aseptic  operation 
as  it  is  generally  understood  by  surgeons  becomes  next  to 
im])ossible.  Xotwithstanding  these  difficulties,  the  dentist 
i>  no  more  justified  in  introducing  infection  by  way  of  the 


42  ASEPSIS 

root-canal,  than  the  general  surgeon  is  in  doing  so  by  way 
of  the  integument. 

The  operative  field  in  root-canal  work  is  the  smallest 
known  to  surgery  and  this  to  some  extent  offsets  the  danger 
of  our  somewhat  loose  technic.  Bacteria  can  infect  only  the 
object  with  which  they  come  into  actual  contact.  Therefore 
the  necessities  of  the  case  only  demand  that  nothing  shall 
enter  the  pulp  chamber  which  may  carry  contamination.  It 
is  the  belief  of  the  writer  that  this  result  may  be  assured  by 
the  simple  technic  which  follows. 

Before  the  canal  is  opened  it  is  a  wise  precaution  to  attempt 
the  sterilization  of  the  coronal  dentin.  I  am  indebted  to 
Grieves  for  suggesting  a  10  per  cent,  solution  of  beechwood 
creosote  in  oil  of  cloves  for  this  purpose.  The  clove  oil  is 
used  as  a  penetrating  menstruum  to  carry  the  creasote, 
which  in  10  per  cent,  solution  is  not  coagulant,  in  the  dentin. 
Where  the  pulp  chamber  has  not  been  opened  or  where  the 
canals  are  blocked  off  by  previous  fillings,  formocresol  is  a 
valuable  agent.  Either  of  these  drugs  must  be  sealed  in  for 
three  or  four  days,  as  it  requires  that  time  to  sterilize  dentin 
by  such  means.  Where  discoloration  of  the  tooth  is  not  an 
objection,  Howe's  silver  reduction  method  may  be  used  and 
the  delay  avoided. 


STERILIZATION  OF  OPERATIVE  FIELD. 

After  the  attempt  to  sterilize  the  coronal  dentin,  the  tooth 
should  be  opened  only  when  blocked  off  by  the  rubber  dam, 
which  should  expose  as  few  teeth  as  are  necessary  to  give  an 
unobstructed  view.  The  dam  should  be  adjusted  in  such  a 
manner  that  there  is  no  possibility  of  leakage  of  fluids  froni 


STKh'iLizA'riox  OF  ori'h'ATni-:  field  43 

tlic  moutli.  Tlic  teeth  iiicliided  should  he  ruhhed  dry  with 
gauze  or  cotton  to  remove  the  mucus,  and  the  entire  field 
then  ])aint('d  with  tincture  of  iodin.  After  this  has  (h'ied  it 
is  washed  oil'  with  alcohol  to  lighten  the  held.  The  coronal 
cavit>'  may  now  be  o{)ened. 

\\  here  cavities  extend  below  the  ginf:;iva,  or  the  crown  is 
wanting,  it  is  necessary  to  prepare  the  tooth  for  the  reception 
of  the  rubber  dam.  This  is  most  conveniently  done  with  the 
manufactured  co])])er  l)ands  which  are  su])plied  for  amalgam 
work.  Tlu-  band  should  be  cut  to  conformity  with  the  gin- 
gival margin  and  articulation  and  be  securely  cemented  to 
})lace  with  a  good  crown-and-bridge  cement.  For  anterior 
roots  the  band  may  be  cut  away  labially  in  such  a  manner 
that  a  flat  back  facing  may  be  ground  to  fit.  By  arranging 
the  facing  so  that  it  does  not  come  into  contact  with  the 
()l)l)osing  teeth  in  mastication,  and  bending  the  pins  together 
to  form  an  arch,  it  will  adhere  to  the  gutta-percha  reasonably 
well  for  two  or  three  days. 

Cotton  and  dressings  used  in  root-canal  work  are  probably 
the  most  frequent  sources  of  contamination.  To  avoid  this 
the  o])erator  should  ha\e  available  a  sufficient  number  of 
sterilized  ])ackages  to  meet  his  daily  need.  The  ])ackage  is 
prepared  as  follows:  a  thick  towel,  large  enough  to  cover 
the  operating  table  is  folded  evenly  to  a  size  about  four  by 
eight  inches.  Upon  one  end  of  this  is  laid  a  small  J.  &  J. 
napkin  folded  twice  upon  itself.  On  the  napkin  are  laid  two 
sections  of  cotton  rolls,  about  two  dozen  J.  &  J.  absorbent 
])oints,  a  number  of  small  cotton  balls  and  at  least  half  a 
dozen  smooth  broaches  wrai)ped  with  cotton.  Three  or  four 
of  the  long  Darby  absorbent  i)oints  will  also  be  found  useful. 
These  dressings  are  now  covered  with  another  folded  nai)kin 
and  the  towel  folded  over  it.    The  whole  is  now  secureK'  but 


44 


ASEPSIS 


not  tightly  wrapped  in  a  piece  of  unbleached  muslin,  which  is 
pinned  to  hold  it  together.  As  many  of  these  packages  as 
may  be  required  are  daily  made  up  and  sterilized. 


Fig.  18. — Sterilizing  room  made  in  closet.     Autoclave  for  goods  in  packages 
and  wet  sterilizer  for  instruments. 


STERILIZATION  OF  DRESSINGS  AND  INSTRUMENTS. 

For  the  sterilization  of  dressings  there  is  nothing  so  abso- 
lute as  the  autoclave  or  high  pressure  sterilizer  (Fig.  18). 


STKUILIZATIOS  OF  hli'l'JSSfNGS  AM)  f XSTRl' M I':XTS     45 

When  subjected  to  stcMiii  under  fifteen  ])(»iin(ls'  i)ressure  for 
twenty  minutes  jjositivc  sterilization  is  assured.  Then  by 
sul)jeetinj:;  to  neji;ati\e  i)ressure  for  about  ten  minutes,  the 
])aeka|;;es  are  rendered  almost  free  from  moisture.  This  is  of 
great  adxantaire  in  preNentinji;  rust  on  tiie  eotton  wrapped 
broaches.  I  liuh-pi'essure  sterilizers  are  somewhat  ex])ensive, 
but  the  certainty  of  sterility  makes  the  expenditure  worth 
while  for  any  dentist  who  does  much  root-canal  work. 

Next  in  efheieney  to  the  autoehive  for  this  purpose  is  an 
ordinary  gas  cooking  range.  Ahnost  any  hirge  vessel  may  be 
arranged  to  su])i)()rt  a  perforated  platform  on  which  the  dress- 
ings may  be  sui)jected  to  live  steam,  without  actually  coming 
into  contact  with  the  l)()iling  water.  After  thirty  minutes 
of  such  treatment,  the  packages  may  be  placed  on  a  tray  and 
])ut  ill  the  oven  to  be  subjected  to  dry  heat  for  an  hour  or  two. 
( 'are  must  be  taken  to  prevent  overheating  the  oven  and  thus 
burning  the  dressings. 

The  Pent/,  sterilizer  is  adxocated  by  many  careful  root- 
canal  workers,  and  i)r()bal)ly  is  efhcient  for  cotton  or  gauze 
laid  loosely  on  the  tra\'.  but  if  such  a  method  of  sterilization 
were  satisfactory  for  goods  in  packages,  one  would  expect 
to  find  it  in  use  in  our  large  hospitals. 

A  mouth  miri'or,  two  or  three  pairs  of  cotton  ])liers,  rubber- 
dam  clani])  forcei)s  and  clamps,  a  ])air  of  collar  ])liers.  a  few 
broach  holders  and  lu-cessary  exca\'ators.  chisels  and  burs 
should  l)e  placed  u])()n  a  perforated  tray  and  sterilized  by 
boiling  for  twenty  minutes  i)rior  to  the  operatin 

Barbed  broaches  and  smooth  broaches  for  carrying  cotton 
dressings  may  \n-  kept  in  alcohol.  \\  idc-iiecked  bottles,  such 
as  the  ordinary  amalgam  ixittle,  are  fitted  with  corks,  into 
the  under  side  of  which  the  broaches  are  stuck  in  such  a 
manner  that  when  the  cork  is  in  the  bottle  the  instruments 


46 


ASEPSIS 


will  be  immersed  in  the  alcohol.  The  addition  of  one  part  of 
oil  of  sweet  almonds  to  nine  parts  of  alcohol,  will  prevent 
rusting,  no  matter  how  long  the  instruments  are  thus  kept. 

Having  made  the  foregoing  preparations,  we  are  now  ready 
to  set  the  table  for  the  operation  (Fig.  19).  The  ordinary 
bracket  table  is  so  unsteady  that  greater  safety  is  assured  by 
using  a  glass  surgical  table,  so  placed  that  it  is  within  easy 


Fig.  19. — Table  set  for  aseptic  root-canal  technic. 


reach  of  the  operator  and  assistant.  To  the  back  of  the  table 
may  be  placed  the  medicaments  likely  to  be  of  use,  such  as 
iodin,  alcohol,  canal  antiseptics,  peroxid  of  hydrogen,  30  per 
cent,  sulphuric  acid,  xylol,  temporary  stopping,  etc.  At  one 
end  a  Bunsen  burner  should  be  arranged,  as  it  is  frequently 
necessary  to  flame  the  cotton  pliers  or  collar  pliers.  An  open 
receptacle,  such  as  a  hair-receiver,  for  waste  material  should 
also  be  provided. 


l\STJaMK.\TAh'ir.\f  47 

The  tahlc  top  is  wijH'd  ofl'  witli  alcoliol  and  {•o\('rcd  with  a 
sterile  towrl  from  one  of  the  packages.  The  i)ackaf^e  should 
be  opened  in  such  a  maimer  that  the  fiii,t,^crs  do  not  eontami- 
nate  its  contents.  The  towel  is  then  removed  with  two  pairs 
of  flamed  forceps  and  spread  U])on  the  table.  The  packapje 
of  dressin<is  is  placed  on  the  end  of  the  towel,  being  sure  that 
they  are  completely  covered  by  one  of  the  folded  napkins. 
On  the  extreme  back  of  the  towel  are  now  set  the  bottles 
containing  the  broaches  in  alcohol.  The  corks  are  removed 
and  reversed  and  set  upon  the  towel  just  in  front  of  their 
respective  bottles.  The  long-handled  broaches  are  then 
placed  in  the  bottles  to  sterilize. 

INSTRUMENTARIUM. 

A  very  good  assortment  of  root-canal  instruments  is  as 
follows: 

1st  bottle — Four  patlifinders  of  assorted  sizes. 

2d  bottle — Four  apexogra])hers  of  assorted  sizes. 

3(1  bottle — Two  XXX  and  two  XX  Uhein  root-picks. 

4th  bottle — Two  X  and  two  fine  Rhein  root-picks. 

The  handles  of  these  instruments  should  be  so  marked  with 
a  file  that  the  size  can  be  determined  at  a  glance. 

5th  bottle — Two  No.  1  and  two  Xo.  2  Kerr  root-canal  files. 

6th  bottle — ^Tw^o  No.  3  and  two  No.  4  Kerr  root-canal  files. 

7th  bottle — Two  No.  5  and  two  No.  0  Kerr  root-canal  files. 

These  instruments  have  had  the  irritating  tendency  to 
loosen  in  the  handles,  but  those  now  being  manufactured 
are  improved  in  this  respect. 

Sth  bottle — Set  of  Oane  root-canal  o])eners. 

0th  bottle — Assorted  sizes  Khein  canal  enlargers. 

The  iiandles  of  all  these  instruments  should  lean  to  the  side 


48  ASEPSIS 

of  the  bottle  next  the  operator.  When  one  is  used  it  is 
returned  to  the  bottle  leaning  in  the  opposite  direction,  thus 
resting  the  instrument. 

Short  handled  instruments  should  be  placed  in  a  covered 
Petri  dish  well  filled  with  alcohol.  A  half  dozen  of  the  three 
smaller  sizes  of  Kerr  root-files,  a  couple  of  small  Young 
broaches  and  a  few  fine  barbed  broaches  make  a  satisfactory 
assortment.  When  a  short-handled  instrument  is  used  the 
fingers  should  be  thoroughly  immersed  as  the  instrument  is 
picked  out  of  the  alcohol.  As  soon  as  they  become  dry  they 
should  be  immersed  again,  otherwise  contamination  of  the 
field  may  be  expected. 

The  assistant  may  set  the  table  while  the  operator  is  wash- 
ing his  hands,  adjusting  the  rubber  dam  and  removing  the 
temporary  filling.  By  this  time  the  instruments  in  the  alcohol 
will  be  sterile  and  the  operation  may  proceed. 

The  cotton  rolls  in  the  sterile  packages  are  for  use  in  the 
event  of  the  inadvertent  puncture  or  tearing  of  the  rubber 
dam  while  the  coronal  cavity  is  open.  By  stretching  the  dam 
a  trifle,  one  of  these  rolls  held  in  forceps  may  be  made  to 
plug  the  opening  while  the  coronal  cavity  is  sealed,  after 
which  a  new  piece  of  dam  should  be  adjusted  before  con- 
tinuing the  operation.  The  rolls  are  also  useful  for  making 
sterile  cotton  swabs  for  the  canal  in  the  following  manner: 
From  a  cork  containing  fine  barbed  broaches  which  have  been 
somewhat  worn  down  by  use,  select  one  of  proper  size, 
sticking  the  barbed  end  into  the  cut  end  of  the  roll  and  giving 
it  a  couple  of  turns.  Upon  withdrawal  the  cotton  fibers  will 
be  wrapped  around  the  instrument  in  such  a  manner  that  they 
will  not  slip  from  it  in  swabbing  out  the  canal.  Still  another 
use  for  the  rolls  is  absorbing  solutions  used  to  irrigate  the 
canal. 


INSTRUMENT  A  HI  I  M  49 

For  use  in  (iui(kl\'  scaliiiu  tli(>  caxity  in  tlu'  vvvut  that  it  is 
necessary  to  clianj^e  the  nihlxT  (hiin  a  iiuiiiIxt  of  small  cotton 
})ellets  are  (lr<»])])e(l  into  incited  i)araliiii  and  allowed  to  l)oil 
for  twenty  minutes.  They  are  then  in(li\i(lually  removed 
witli  sterile  cotton  })Hers  and  laid  on  a  sterile  towel  to  cool. 
When  the>'  have  hardened  they  are  ])Iaced  in  a  screw-top 
bottle  and  kv\)t  in  a  coiix-eiiieiit  place  on  the  table.  When 
needed  it  is  only  necessary  to  take  one  in  the  cotton  pliers 
and  hold  it  an  instant  in  the  Bunsen  flame,  when  it  may  be 
pressed  into  the  cavity  effectively  sealing  it  while  the  dam  is 
being  changed. 

Gutta-percha  points  should  be  prepared  for  use  as  follows: 
Dip  in  iodin  and  place  on  sterile  glass  slab  to  dry,  wash  oti' 
with  alcohol,  and  then  j)lace  in  an  alcohol  bath  in  a  suitable 
covered  container. 


CHAPTER  IV. 
INSTRUMENTATION  OF  THE  CANAL. 

OBTAINING  FREE  ACCESS. 

It  has  been  pointed  out  that  before  entering  the  pulp 
chamber  an  attempt  should  be  made  to  sterilize  the  coronal 
dentin.  Thereafter  the  rubber  dam  should  be  applied  and 
the  coronal  cavity  so  shaped  that  free  direct  access  may  be 
had  to  each  canal  in  a  line  with  its  long  axis.  It  is  unfortu- 
nate that  this  often  means  extensive  destruction  of  sound 
tooth  substance,  but  even  if  the  whole  crown  must  be  sacri- 
ficed the  procedure  is  justified.  The  coronal  opening  corre- 
sponds to  the  primary  incision  in  any  other  surgical  operation, 
and  as  the  object  here  is  the  safety  of  the  root,  as  much  of  the 
crown  should  be  sacrificed  as  may  be  necessary  to  prevent 
failure  (Fig.  20) .  Wherever  possible,  the  natural  walls  of  the 
pulp  chamber  should  be  preserved,  as  these  will  guide  the 
broach  naturally  into  the  canals.  The  best  method  is  to 
enlarge  the  cavity  of  access  until  the  roof  of  the  pulp  chamber 
consists  of  only  a  thin  layer  of  dentin,  and  then  remove  this 
with  chisels  and  hoes  (Fig.  21). 

In  bicuspids  and  molars  it  is  always  necessary  to  enlarge 
mesial  cavities  well  into  the  occlusal  surface,  and  frequently, 
when  the  decayed  or  filled  cavity  is  distal,  it  will  be  expedient 
to  cut  somewhat  into  the  mesiobuccal  surface  as  well.  Those 
familiar  with  the  Black  system  of  cavity  preparation  will 
understand  how  to  shape  these  cavities  so  as  not  to  weaken 


OHTAIMXC  FREE  ACCESS 


51 


the  tooth.  The  cutting  is  l)est  done  with  a  round  or  inverted 
cone  bur,  eare  heiufj  used  to  ])revent  its  phnifjiug  into  the 
pulp  chamber.    No  overlianging  walls  should  be  left  at  any 


OPCMNG  IN  GORRLCT     0PCN1NG  IN  WRONG  OPE.NIN&  wlDt  CNCXlGM 
POSITION  BUT  NOT  PO&TION.  BUT  TOO  OCtP 

WlOe  ENOUGH 

Fig.  20. — Incorrect  tcchnic. 


])()int.  In  incisors  and  cuspids  the  lingual  wall  nuist  generally 
be  cut  away,  no  matter  where  the  cavity  of  decay  exists. 
Enough  dentin  should  be  removed  toward  the  incisal  surface 
to  completely  expose  the  horns  of  the  ])ulp.  In  either  class 
of  teeth,  should  the  broach  bind  on  any  of  the  cavity  walls, 


OPtNTOROOr  BRCAK  DOWN  IN  TOOTH  CORRLCTLY 

or  PULP  CMAMBCR.   TO  PULP  GMAMBCR.  OPCNLD. 

Fig.  21. — Correct  technic. 


when  inserted  in  the  canal,  more  cutting  should  be  done  in 
that  direction  until  the  broach  is  absolutely  free. 
The  conscientious  operator  will  have  made  a  careful  study 


52  INSTRUMENTATION  OF  THE  CANAL 

of  dental  anatomy  and  be  aware  of  the  normal  number  and 
location  of  the  canals  in  each  type  of  tooth.  Variations  from 
the  typical  are  to  be  expected  and  looked  for.  There  are  often 
two  distal  canals  in  the  lower  first  molar.  The  mesiobuccal 
root  of  the  upper  first  molar  sometimes  contains  two  canals. 
Thefe  are  not  a  few  lower  second  molars  with  only  one  large 
canal  and  upper  second  molars  with  one  or  two  canals  only. 
Lower  bicuspids  are  found  with  two  canals  and  upper  second 
bicuspids  frequently  have  two.  I  have  encountered  three 
lower  bicuspids  with  two  well-defined  canals  and  a  few  upper 
cuspids  with  a  second  canal  running  into  a  rudimentary  root. 
The  lower  third  molars  may  have  from  one  to  four  canals  and 
the  upper  as  many  as  seven.  The  possible  presence  of  such 
abnormalities  should  serve  to  keep  the  operator  always  on 
guard,  for  no  matter  how  well  the  canals  which  are  found  are 
managed,  an  untreated  canal  will  entirely  vitiate  the  result. 
On  the  other  hand,  if  a  canal  cannot  be  found  it  will  do  no 
good  to  form  an  artificial  one,  and  this  attempt  generally 
results  in  puncture  of  the  root. 

When  difficulty  arises  in  the  search  for  the  canals,  it  is 
generally  because  the  floor  of  the  pulp  chamber  has  been 
mutilated.  Other  factors  tending  to  impede  progress  are 
insufficient  access,  previous  canal  fillings  or  chips  of  dentin 
in  the  canal  orifice.  If  the  radiograph  indicates  that  the 
canals  are  blocked  by  fillings,  some  solvent  should  be  used. 
For  gutta-percha  the  pulp  chamber  should  be  flooded  with 
xylol,  which  in  a  few  minutes  will  so  soften  this  material  that 
the  finder  will  slip  into  the  canal.  If  the  obstruction  is  of 
cement  or  a  proprietary  root-filling,  the  canals  may  be  located 
by  painting  the  floor  of  the  pulp  chamber  with  iodin.  When 
this  is  washed  out  with  alcohol  the  root-filling  will  retain  the 
stain. 


KXl'LOUATIUX   OF   THE  CAXAL  53 

If  llic  orifice  nf  tlic  <-;iiiiil  is  filled  willi  (•liii)S  of"  dentin,  pulp 
stt)iu's  or  lianleiied  pnlp  (issne,  a  small  ]>ieee  of  sodinin- 
potiissinni  slionld  he  |)laeed  in  the  pulp  cliamlx-r  and  s])read 
eMMily  ()\'er  the  lloor.  A  hroken  root  pick  sliai'pened  to  a 
])oint  is  then  nsed  to  systematically  swee])  this  snrl'aee  until 
it  becomes  en^a^ed  in  the  orifice  of  the  canal.  \Vhen  this 
fails,  occasionally  a  .")()  ])er  cent.  snli)lnn'ic  acid  followed  hy 
l)ieari)()nate  of  soda  will  succeed.  Tlie  temptation  to  use  a 
i)nr  in  an  nttemi)t  to  unco\-er  the  canal  in  these  cases  is  some- 
times almost  irresistihle,  hut  to  do  so  is  sure  to  complicate 
matters  still  further. 

EXPLORATION  OF  THE  CANAL. 

Having  located  the  canals  by  whatever  means,  the  work 
ill  the  canal  proper  is  begun  by  exploring  to  its  apical  extrem- 
ity. Upon  the  complete  accomplishment  of  this  task  the 
success  of  the  sul)se(|uent  work  depends.  There  are  certain 
canals  which  cannot  be  so  ex})l()rc(l  by  any  technic  at  ])resent 
available,  but  the  proportion  of  such  is  much  less  than  it 
would  seem  to  the  inexperienced. 

A  fine,  smooth  broach  of  ])iano  wire  is  the  only  instrument 
which  can  be  depended  upon  to  do  this  part  of  the  work  with 
safety.  The  Khein  root  i)ick,  the  Twentieth  Century  ])ath- 
finder  and  the  Kci'r  root  ])i-obe  are  all  instruments  designed 
for  this  i)urj)ose.  The  Kerr  .set  contains  the  finest  instrument 
of  this  t,\pe,  not  much  thicker  than  a  hair,  which  is  often  \erv 
useful,  but  these  probes  are  made  of  blued  steel,  w  hich  makt's 
thcni  (li(Ii(iilt  t(»  sec  in  operation.  The  iiathhndcr  is  a  long 
delicate  instrument  with  which  good  work  may  be  accom- 
])lishe(l,  but  the  flexibility  of  the  long  shank  confuses  the  sense 
of  touch  to  some  degree. 


54  INSTRUMENTATION  OF  THE  CANAL 

Crane  Canal  Openers. — It  is  not  unusual  to  encounter  canals 
so  plugged  with  organic  debris  or  other  obstruction,  that 
when  pressure  is  made  upon  the  smooth  broach  the  point 
buckles,  thus  retarding  its  progress.  For  the  purpose  of 
overcoming  this  I  have  recently  had  made  by  the  Donaldson 
Broach  Company  a  set  of  canal  openers.  This  consists  of 
four  instruments  of  the  root-pick  type,  the  modification  being 
that  the  working  points  are  of  varying  lengths,  thus  increasing 


Fig.  22. — Crane  opener  for  difficult  canals. 

the  relative  length  of  the  shanks.  The  No.  1  opener  has  a 
fine  point  one-eighth  of  an  inch  long;  No.  2  is  one-fourth  inch; 
No.  3  is  three-eighths  and  No.  4  one-half.  If  these  instru- 
ments are  used  successively,  beginning  with  the  shortest,  they 
will  enable  the  operator  to  explore  difficult  canals  without 
the  buckling  of  the  instrument  interfering  with  the  sense 
of  touch.  After  the  longest  opener  has  been  buried  to  its 
shank  in  the  canal,  the  root-pick  will  usually  complete  the 
exploration. 


Hh:M()\  ISC  ixdh'c.w/c  M.\ri-:i:i.\L  55 

Im)!-  niutiiic  work  llic  llliciii  picks,  wliidi  (■nine  in  fonr 
si/i'S,   aiT  ;i(liiiii';ililc. 

Select  iiiu'  tlie  sniallcst  si/e  the  attemi)t  is  made  to  follow 
tlu'  canal  to  the  apical  opeiiiiifi;  l)y  a  scries  of  i)usiiiii^  and 
pickiiifi  motions  (Fig.  25,  A).  If  the  ])rogress  of  the  hroach 
is  sto])])e(l  a  comma-like  turn  given  to  the  extreme  point  of 
the  instnmient  will  frequently  allow  it  to  proceed.  If  this 
fails,  sometimes  a  slight  quarter-turn  twisting  motion  given 
just  at  the  imi)act  of  the  picking  motion  will  cause  it  to  i)ass 
the  ohstniction.  Xo  great  force  should  be  used,  howc\'cr, 
and  where  ])urely  mechanical  exploration  fails  chemical  aid 
is  indicated.  This  should  not  be  undertaken  blindly,  but  the 
cause  of  the  obstruction  should  be  ascertained  if  possible. 


THE   CALLAHAN  METHOD    OF    REMOVING    INORGANIC 
MATERIAL. 

Acids  should  be  used  for  inorganic  blockade,  alkalies  for 
organic,  and  suita])le  solvents  for  previous  canal  fillings. 

The  i)rincipal  acids  used  for  this  ])urpose  are  30  per  cent, 
sulphuric,  i)henolsul])lionic  and  hydrochloric.  The  life-work 
of  Callahan  with  the  sulphuric  acid  gives  it  preeminence 
and.  where  indicated,  it  renders  a  useful  service.  An  appli- 
cator may  be  made  of  fine  iridioplatinum  wire,  filed  to  a  ta])er 
]K)int  and  somewhat  roughened  with  a  coarse  file.  A  satu- 
rated solution  of  bicarbonate  of  soda  in  sterile  water  should 
sul)se(|uently  be  used  for  the  doultlc  ])ni-i)ose  of  neutralizing 
any  fn-e  acid  remaining,  and  forcing  out  the  dei)ris  i)y  the 
bubblinii;  which  ensues. 


56  INSTRUMENTATION  OF   THE  CANAL 

THE  SODIUM-POTASSIUM  METHOD. 

The  principal  alkalies  are  sodium-potassium,  sodium- 
dioxid  and  sodium-hydroxid.  Of  this  group  the  sodium- 
potassium  is  easiest  to  handle  and  meets  all  the  requirements. 
The  best  form  is  Schreier's  paste,  which  was  obtainable  in 
Germany  before  the  war,  but  the  S.  S.  White  Company 
makes  a  preparation  which  is  quite  satisfactory.  It  comes 
in  a  small  glass  tube  which  can  be  kept  sealed  with  wax  when 
not  in  use.  In  use  the  tube  is  nicked  with  a  knife-edged  file 
just  above  the  point  where  the  silver  color  shows  the  alloy 
unchanged,  and  the  tube  broken  off  at  this  point.  A  white 
substance  forms  at  the  top  of  the  tube  from  contact  with  air 
and  this  should  be  discarded.  The  point  only  of  the  pick  is 
dipped  into  the  sodium-potassium  and  it  should  merely  be 
painted  with  the  alloy;  that  is,  no  lumps  should  adhere  to 
the  instrument.  It  may  be  more  impressive  to  say,  "Use 
sodium-potassium  only  in  homeopathic  doses."  When  this 
substance  comes  into  contact  with  moist  organic  material 
there  is  a  miniature  explosion,  attended  by  flame  and  smoke, 
caused  by  the  rapid  oxidation.  In  this  reaction  some  of  the 
organic  material  is  actually  consumed  and  some  is  saponified. 
The  use  of  sodium-potassium  in  the  canal  is  only  occasionally 
attended  by  explosion,  hence  the  saponified  tissue  must  be 
washed  out  of  the  canal,  for  which  purpose  alcohol  is  an 
efficient  medium.  Repeated  applications  will  eventually 
remove  any  organic  blockade. 

As  previously  stated,  alkalies  are  indicated  for  organic 
obstructions,  but  where  the  closure  is  caused  by  a  calcific 
nodule  or  a  constriction  of  the  canal  walls,  sodium-potassium 
will  more  quickly  effect  a  passage  than  acids.  This  is  because 
it  destroys  the  organic  cementing  stroma  of  the  dentin  as  well 


Till':  SonilM    I'OTASSIIWf    METHOD  ."j? 

as  till'  ()rj,'iuiic  nuittcr  in  tlic  (Iciitin.il  tiil)iili,  Iciiviiijf  flic 
iiiorUMiiic  portion  in  such  t'oi'ni  that  it  is  readily  |)iil\cri'/.c(l 
l)y  tlir  hroacli.  Tims  it  is  the  hcst  clicniicai  aid  for  routine 
use  in  removing  natural  obstructions. 

Gutta-percha  is  the  most  i"re(iuently  encountered  artificial 
obstruction.  For  dissohin<:j  this,  chloroform,  eucaly])tol  or 
xylol  may  Uc  used.  The  latter  ])ossesses  many  advantages 
over  the  other  two  and  in  a  few  minutes  will  so  soften  the 
hardest  gutta-i)ercha  that  the  pick  will  ])ass  through  it. 

Obstructions  caused  by  ])roprietary  root  pastes  will  be 
slowly  softened  by  sulphuric  acid,  in  the  rare  cN'ent  that  they 
are  hard  enough  to  offer  any  resistance  to  the  i)assage  of  the 
pick.  Gold  or  cement  nnist  be  ])ainstakingly  ])icked  out. 
A  stiH",  i)ointed  instrmnent  made  of  a  broken  root  ])ick 
is  most  useful  for  this  puri)ose. 

Broken  instruments  offer  the  greatest  difficulty  of  any 
canal  obstruction.  It  ma\'  here  be  ])()inted  out,  however, 
that  this  does  not  ai)i)ly  to  smooth  instruments  broken  otf 
in  the  picking  and  i)ushing  motion.  If  these  are  sim})ly 
ignored  for  the  time  being  and  the  ])icking  and  pushing 
resumed  with  a  new  instrument,  the  broken  portion  will  soon 
ride  out  of  tlie  canal,  but  where  an  insti'ument  is  broken 
while  being  screwed  into  the  canal  further  exploration  is  often 
im])ossil)le.  By  relocated  use  of  sodium-potassium  on  a  root 
])ick,  it  is  sometimes  ])ossible  to  make  a  ])athway  alongside 
of  the  obstruction,  and  then  a  twist  broach  nuiy  be  passed 
into  this  and  twisted  around  and  around  to  the  right,  without 
]H'rmitting  it  to  advance  into  the  ()])ening.  When  this  does 
not  work  it  is  feasible  occasionally  to  continue  the  ])icking 
alongside  of  the  broken  instrument  and  reenter  the  canal 
at  a  i)oint  ajjical  to  it.  When  the  broken  i)iece  projects  peri- 
apieally,  extraction  or  root-resection  is  indicated. 


58 


INSTRUMENTATION  OF  THE  CANAL 


THE  DIAGNOSTIC  WIRE. 

After  the  canal  has  been  explored  as  far  as  possible  by  the 
foregoing  method,  successive  sizes  of  root  picks,  carrying 
smallest  quantities  of  sodium-potassium  should  be  used, 
passing  them  to  the  farthest  point  of  exploration  and  then 
pressing  around  the  side  walls  of  the  canal  (Fig.  26,  A).  In 
this  way  the  opening  may  be  made  large  enough  for  the 
insertion  of  a  diagnostic  wire  (Fig.  23).  For  this  purpose 
there  is  nothing  better  than  a  strand  of  ordinary  braided 


Fig.  23. — Diagnostic  mres. 


picture  wire.  Enough  of  this  to  last  a  life-time  can  be  bought 
for  five  or  ten  cents,  and  it  has  all  the  qualities  necessary  for 
this  use.  Where  the  caliber  of  the  canal  permits,  the  diag- 
nostic wire  may  be  wrapped  with  cotton  fibers  and  saturated 
with  any  medicinal  agent  indicated.  The  end  of  the  wire 
which  is  to  remain  in  the  pulp  chamber  should  be  given  a 
turn  around  the  beaks  of  the  cotton  pliers  so  that  it  may 
readily  be  grasped  for  withdrawal. 

After  the  insertion  of  the  diagnostic  wire  a  radiograph  will 
indicate  the  extent  to  which  the  canal  has  been  explored, 
and  will  be  suggestive  of  subsequent  procedure.    If  a  portion 


I'lnC   DIAMSOSTIC    W  IliE 


59 


of  tlu'  ciuiiil  is  uiK'Xi)l()r(>(l,  wlicrc  tliis  is  str;iif,'lit  a  still"  ])ick 
or  fine  root  file  nia\'  l)c  used  with  coiisidcralilc  lorct-  to  coin- 
plctc  I  lie  (ipciiini;'.  1 1'  1  he  canal  is  cui'xcd,  the  smooth  hroadi 
should  he  curxcd  to  approximately  the  same  decree  and  the 
Ucntle  pushiiii;"  and  pickitiij:  motions  resumed,  with  the  aid 
of  the  iiulieated  chemical. 

A  conunou  cn-or  in  deahn^  with  curxcd  roots  is  to  enlarge 
the  eanal  with  burs  or  reamers  in  the  (lirection  of  the  lon<i 
axis  of  the  unexplored  portion.  This  jjossihly  mijj;ht  be  tried 
as  a  last  resource,  but  to  mutilate  the  canal  with  any  instru- 


USING  BROACM 
AS  &IMLE.T. 


USING  AN  ENLAR&N&  ThE.  APICAL 

EN&NC  INSTRUMtNT  WITH   DOWNWARD 

PRLSSURE. 


FiLi.  24. — Common  error; 


ment  prior  to  exi)lorin<i  to  the  ai)ical  foramen  is  to  invite 
almost  certain  failure  to  accomplish  the  desired  result. 

The  attempt  to  use  a  broach  of  any  kind  as  a  fjimlet  or  to 
use  any  instrument  rex'olved  by  the  engine  will  often  result 
in  forcing  dei)ris  ahead  until  the  canal  is  hopelessly  occludi'd. 
The  formation  of  an  offset  or  shoulder,  which  will  dellect 
the  broach  \\  hen  again  used,  the  puncture  of  the  root,  or  the 
fracture  of  the  instrument  within  the  canal,  are  otlu-r  ])otent 
])robabilities  of  such  indiscretion  (Fig.  L'4). 

AVhen  the  use  of  the  canal  o])eners  fails  to  oihmi  the  canal 
the  use  of  the  fini'st  Kerr  root  file  or  ^ Dung  broach  in  (piarter 


60  INSTRUMENTATION  OF  THE  CANAL 

turns  is  sometimes  indicated,  but  the  frequent  withdrawal 
and  cleansing  of  the  instrument  must  not  be  neglected. 

If  the  canal  cannot  be  explored  to  the  end,  it  should  be 
enlarged  as  far  as  possible,  and  the  unfilled  portion  of  the 
root  subsequently  resected. 

Where  previous  partial  root-canal  fillings  are  found  they 
should  be  completely  removed  prior  to  the  attempt  to  explore 
the  remainder  of  the  canal.  Most  frequently  an  offset  will 
have  been  formed  at  the  extremity  of  the  filling,  by  the  pre- 
vious operation  (Fig.  25).  It  is  quite  difficult  in  such  event 
to  find  the  continuation  of  the  canal  proper.     This  is  best 


Fig.  25. — Offset  clearly  shown  in  distal  canal  of  first  molar. 

done  by  giving  the  comma-shaped  curve  to  the  end  of  the 
root  pick.  Then  by  picking  away,  revolving  the  instrument 
just  a  little  with  each  pick,  the  point  will  often  slip  past  the 
shoulder  and  continue  on  its  apical  journey.  No  attempt 
should  be  made  to  eliminate  the  shoulder  until  after  the 
extremity  of  the  canal  has  been  opened  by  the  smooth- 
broach  sodium-potassium  method,  so  as  to  admit  the  free 
insertion  of  the  largest  size  Rhein  pick.  Then  by  adherence 
to  the  technic  about  to  be  described  for  enlarging  and  shaping 
the  canal,  the  shoulder  may  be  so  rounded  off  that  it  will 
offer  no  interference  in  the  placing  of  the  filling. 


EXLARUl.Mi    Till-:   U(K)T-C.\.\ AL 


Gl 


ENLARGING  THE  ROOT  CANAL. 

ll;i\iiiu'  ic;i(lic(l  llic  |)ci-i;ii)ical  tissue  hy  sninc  lucaiis,  tlie 
next  stop  is  to  iMilar^o  and  rcshaiK*  tlie  canal,  thercl)y  inci- 
dentally removing;  most  of  its  orifjinal  content,  especially  if 
judicious  use  is  made  of  sodium-i)otassium.  The  object  is  to 
make  the  canal  of  such  calil)cr  that  a  sufficiently  firm  •gutta- 
percha ])oint  may  he  em])loyed  in  filling:;  it,  and  to  shai)e  it 
to  a  conical  form,  so  that  when  pressure  is  brought  to  bear 


HNDING  the: 
CANAL. 


ELNLARGNG 
THL  CAIOAL. 


tNLARGNG  THC 
APICAL  OPENING 


Fig.  26. — Correct  techiiic. 


on  the  *iutta-i)ercha  cone  at  the  canal  orifice,  it  will  be  i)acketl 
simultaneously  against  the  side  walls  and  the  apex  of  the 
canal.  Correct  cavity  preparation  is  as  essential  to  good  canal 
fill  ill  (I  as  to  coronal  filling. 

The  desired  result  is  safcl\'  obtained  by  the  use  of  a 
graduated  series  of  Kerr  root-canal  files.  ^'oung  broaches, 
Donaldson  barbed  broaches,  or  Twentieth  Century  rat-tail 
files  may  be  emi)loyed,  but  the  Kerr  file  offers  the  most 
advantages. 


62 


INSTRUMENTATION  OF  THE  CANAL 


The  instrument  first  used  must  be  of  the  smallest  size  and 
of  no  larger  gage  than  the  last  smooth  broach  used  in  the 
exploring  operation.  With  gentle  pressure  this  is  pushed  to 
the  end  of  the  canal  and  withdrawn  with  lateral  pressure. 
This  is  repeated  again  and  again,  always  making  the  broach 
scrape  toward  the  crown,  never  toward  the  apex,  curetting 
systematically  all  around  the  canal  (Fig.  26,  B).  The  file 
should  never  be  twisted  into  the  canal,  but  its  insertion 
may  be  aided  by  minute  quantities  of  sodium-potassium 
(Fig.  27,  A.) 

ABC 


broach  too 
large:. 


FIGHTING  THE. 
CANAL. 


BROACH 
BINONG  AT  ANGLE.. 


Fig.  27. — Incorrect  technic. 


The  next  size  larger  file  is  now  substituted,  in  the  same 
manner  pushing  it  to  the  apical  opening  and  shaving  the 
walls  of  the  canal  only  upon  withdrawal.  By  using  succes- 
sively larger  sizes  of  files  and  repeating  the  technic  just 
described,  the  canal,  even  if  curved  or  twisted,  can  be 
enlarged  to  any  size  and  will  be  formed  to  a  conical  shape. 
(Fig.  28). 

The  enlargement  of  the  canal  only  upon  the  withdrawal 
of  the  instrument  tends  to  carry  most  of  the  debris  into  the 
pulp  chamber.    This  may  be  blown  out  from  time  to  time 


^f^.\.\(;l■:M^':.\T  of  r/ir:  M'Jcal  ui'K.Mxa        G3 

witli  tlic  {•lii])  l)I()\\('i-.  l)Ut  while  this  is  bciiifi  done  the  hroacli 
shoiihl  iih\;i\s  rciiKiiii  in  1  he  caiinl  to  l)h)cl<  tlic  apical  opening,'. 
The  toilet  of  llie  canal  is  acconii)lislie(l  with  hydroffeii- 
])ero\i(l,  lo  which  hichloi'idc  of  iiici'ciii-y  inav  he  added  in 
])r()i)ortion  of  1  to  odd,  if  desired.  A  droj)  is  ])laeed  at  the 
canal  orifice  and  is  u'cntly  worked  into  the  canal  with  a  fine 
absorbent  ])oint.  (are  must  he  cNcrcised  to  ])re\'ent  blocking 
the  canal  with  the  cotton,  as  this  would  cause  elVervescence 
to  take  place  a])ically. 


MANAGEMENT  OF  THE  APICAL  OPENING. 

The  nianaiicnieut  of  the  ai)ical  opening  dei)ends  upon  the 
tjpe  of  fining  to  be  inserted.  ^Yhere  periapical  conditions 
are  still  normal  and  it  is  desired  to  confine  the  filling  entirely 
within  the  canal,  the  ai)ical  o])ening  should  not  be  enlarged, 
but  should  remain  as  nearly  noi'uial  as  ])ossible.  Where 
])eriai)ical  destruction  has  occurred  and  it  is  desired  to  })rt)jcct 
the  filling  material  to  form  a  cap  for  the  root  apex,  the  apical 
opening  should  be  more  or  less  enlarged  depending  upon  the 
degree  of  disorganization.  The  Twentieth  Centiu'y  apcxog- 
rapher,  or  apex  curette  is  an  instnnneut  ideall\'  constructed 
for  this  delicate  task.  The  finest  size  will  ivadily  pass  through 
the  apical  foramen  of  the  average  tooth  which  has  undergone 
the  foregoing  treatment,  but  will  catch  just  a  trifle  upon 
withdrawal,  thus  enlarging  the  lumen  and  drawing  the 
debris  into  the  canal  (Fig.  2(),  D.  Where  the  natural  o])ening 
is  too  small  to  pei'init  the  fre(>  ])assage  of  the  smallest  instru- 
ment, it  may  be  worked  through  by  alternately'  giN'ing  quarter 
turns  and  withdrawing  the  instrument.  There  are  several 
sizes  of  apexograjihers,  and  by  using  them  successively  the 


64 


INSTRUMENTATION  OF  THE  CANAL 


apical  opening  can  be  safely  enlarged  to  meet  the  require- 
ments of  the  case. 

In  curved  or  twisted  canals,  the  smooth  broach  used  in 
exploring  will  usually  come  out  of  the  canal  so  bent  to 
conformity  that  it  may  be  readily  reinserted.  A  broach  so 
shaped  should  be  laid  aside  as  a  pattern  by  which  to  bend 


A  B 

Fig.  28. — The  result  of  one  hour's  work  by  technic  herein  described. 
A,  case  as  it  presented;  B,  diagnostic  wire  in  position. 


each  instrument  subsequently  used  in  the  canal  (Fig.  28). 
Sometimes  it  is  even  expedient  to  bend  the  gutta-percha 
point  to  conform  to  this  pattern. 

After  enlarging  the  apical  opening  the  canal  is  again  washed 
out  with  hydrogen-peroxid  and  is  then  ready  for  the  process 
of  disinfection.  ,  h 


CHAPTER  V. 

THERAPY. 

TiiK  upward  ])r()gress  of  dentistry  has  been  inai-ked  from 
the  be^iimiiig  by  a  tendeney  to  perfect  tlie  ]>iir(ly  mechanical 
and  compromise  with  the  t]iera])euticah  In  the  struggle  to 
reconstruct  our  root-canal  technic  to  meet  the  requirements 
of  adxanced  medical  thought  history  has  repeated  itself. 
While  many  operators  are  capable  of  opening  and  filling 
root-canals  in  a  satisfactory  manner,  it  is  doubtful  if  any 
thoughtful  dentist  can  approach  root-canal  work  with  the 
same  degree  of  assurance  that  he  would  undertake  the  making 
of  an  inlay  or  a  crown.  The  cause  of  this  hesitancy  lies  in 
the  uncertainty  of  accomplishing  the  eradication  of  the  infec- 
tion. Tntil  some  scientifically  correct  method  of  making 
cultures  in  root-canal  work  is  determined,  the  sealing  of  the 
canal  will  be  fraught  witli  the  dangerous  ])(»ssii)ility  that  the 
infection  still  ])ersists.  While  awaiting  this  discovery  a  care- 
ful study  should  be  made  of  the  possibilities  and  limitations 
of  sterilization  in  periapical  disease.  Such  a  study  recjuires  a 
visualization  of  the  ])athological  condition  of  the  tooth  and 
its  investing  tissues. 

In  a  typical  case  of  pcria])ical  infection  the  tooth  is  ])ul])less, 
and  tile  canal  contains  more  or  less  infected  organic  matter. 
Tlic  contents  of  the  dentinal  t  iibuli  lia\  c  inidergone  a  change 
due  to  the  action  of  the  inxading  bacteria.  This  degx-nera- 
tion  may  be  confined  to  the  inunediate  region  of  the  canal. 
5 


66  THERAPY 

but  except  in  cases  of  short  standing,  it  extends  well  toward, 
if  not  quite  to,  the  dentocemental  junction.  Wherever  this 
change  has  occurred  the  dentin  is  not  only  dead,  but  infected. 
Externally  the  cementum  covering  the  root  apex  may  be 
necrotic  to  a  greater  or  less  extent  and  saturated  with  the 
products  of  infection. 

Of  the  investing  tissues  the  attachment  of  the  apical  fibers 
of  the  pericementum  has  been  destroyed,  and  this  destruc- 
tion often  extends  to  the  fibers  of  the  oblique  groups  as  well. 
To  the  extent  to  which  this  detachment  has  deprived  the 
cementum  of  its  blood  nutrition,  an  irreversible  change  has 
occurred  in  the  hard  tissues. 

The  cancellous  bone  surrounding  this  necrotic  portion  of 
the  root  has  undergone  a  rarefying  osteitis,  in  which  process 
an  infected  granulation  tissue  has  been  substituted  for  the 
normal  bone.  The  surface  of  this  proliferating  tissue  which 
approximates  the  necrotic  tissue  has  a  tendency  to  undergo 
an  indolent  liquefaction,  and  in  advanced  granulomata  this 
metamorphosis  also  takes  place  where  the  soft  tissue  comes 
into  contact  with  the  bone.  In  either  instance  the  hard  tissue 
deteriorates.  The  cementum  becomes  roughened  and  the 
bone  becomes  softened. 

If  the  foregoing  clinical  picture  is  in  accordance  with  the 
facts,  it  must  be  acknowledged  that,  in  cases  of  periapical 
infection,  infection  exists  in  the  following  sites:  (1)  The 
canal  and  canal  walls;  (2)  the  dentinal  tubuli;  (3)  the  apical 
cementum;  (4)  the  granulation  tissue  investing  the  apex; 
(5)  often  in  the  bone  adjacent  to  the  granuloma.  Further, 
it  must  be  recognized  that  each  of  these  areas  is  dependent 
upon  or  contributory  to  the  others,  hence  it  cannot  be 
assumed  that  sterilization  is  complete  until  the  infection  in 
each  of  these  sites  has  been  eliminated. 


t/*S7i    OF    UISIM'ECTASTS   1  .\    ROOT  f'.l.V.iy.,S  07 

The  difficulty  of  tliorouijlily  stcrili/jiif^  tlicsc  iiitcnh'jxMulciit 
s(>iits  of  iiif('<-tioii  is  ;uit,MiuMit('(l  l)y  tlic  fact  tliiit  hotli  lixiiij; 
and  dead  tissues  arc  inxoKcd.  The  researches  of  (and, 
ralif\  iiii;"  and  ainphfyini:,-  t  he  HikHiii^^s  of  many  |)re\ioiis  in\cs- 
ti^^ators,  ai'e  decidedly  con\iiiein^^  in  the  conchision  that 
infections  in  h\in<i;  tissue  can  seldom  he  overcome  by  satu- 
I'atinu'  them  with  dru,ii;s  stronii;  enonuii  to  destroy  the  tissue 
cells.  In  dead  tissue,  on  the  other  hand,  (lei)en(lence  must 
be  i)laced  ui>on  the  germicidal  efl'ect  of  poisons  l)rou<,dit  into 
actual  contact  with  the  invading  organisms.  It  would  ai)])ear, 
then,  that  the  attempt  to  sterilize  both  lixiiig  and  dead  tissue 
b\'  the  same  agency  is  irrational  and  im])ractical)le. 

With  these  facts  in  mind  let  us  proceed  to  a  consideration 
of  the  most  widely  accepted  methods  of  tooth  treatment  in 
an  efiort  to  determine  why  they  are  successful  and  wherein 
thev  fail. 


USE  OF  DISINFECTANTS  IN  ROOT  CANALS. 

For  the  i^urpose  of  disinfecting  dentin  de|)endence  has 
always  been  placed  on  the  action  of  drugs.  At  first  em])ir- 
ically,  and  latterly  more  scientifically,  the  dentist  has  sought 
to  aceomi)lish  with  disinfectants  in  the  teeth  what  the  general 
surgeon  has  also  attemi)ted  in  other  tissues.  The  trend  of 
niddein  surgery,  however,  is  to  place  more  and  more  depend- 
ence upon  tlie  vital  resistance  of  the  tissues.  By  control  of 
the  inlhiimnatory  reaction,  infection  is  inhibit(>d  and  rei)air 
ensues.  In  dead  tissue,  on  the  contrai'y,  thei'e  is  no  inflam- 
matory reartioii  to  control,  and  sterilization  can  only  be 
elfected  by  the  direct  action  of  bactei-ial  poixnis.  TJu' 
greatest  drawback  to  success  in  this  necessity  is  the  dilJicultx- 
of  confining  the  treatment  to  the  canal,  for  agents  wlp'h 


68  THERAPY 

might  be  depended  upon  to  sterilize  the  canal  and  dentin  are 
generally  so  inimical  to  the  vitality  of  the  periapical  tissues 
that  we  have  been  repeatedly  warned  by  careful  investigators 
to  discontinue  the  use  of  all  irritating  drugs.  Other  investi- 
gators, equally  careful,  claim  that  only  by  the  use  of  such 
drugs  can  dentin  be  sterilized,  and  that  periapical  damage  is 
due  to  faulty  technic,  rather  than  the  inherent  property  of 
the  medicament. 

Light  may  be  thrown  upon  this  controversy  by  a  considera- 
tion of  the  theory  that,  in  destroying  bacteria  by  the  use  of 
drugs,  there  is  most  probably  a  definite  chemical  reaction  by 
which  the  characteristics  of  both  bacterium  and  drug  are  lost 
and  inert  substances  produced. 

As  in  any  chemical  reaction  an  excess  of  either  of  the 
factors  will  remain  unchanged  with  all  its  original  character- 
istics. In  the  nice  reactions  which  Buckley  has  worked  out 
to  show  the  rationale  of  formocresol  medication  this  pos- 
sibility is  not  accentuated,  although  he  is  insistent  upon  the 
use  of  minimum  quantities  of  this  drug.  It  would  be  fatuous 
to  deny  that  many  teeth  have  been  restored  to  health  and 
usefulness  b}^  the  aid  of  this  and  other  powerful  drugs,  but 
this  result  has  been  obtained  by  a  chance  happening  upon 
just  the  proper  amount  of  the  remedy  for  the  particular  case; 
where  used  in  excess  nothing  but  harm  has  resulted. 

THE  HOWE  SILVER  NITRATE  METHOD. 

The  treatment  of  root-canals  by  a  silver  reduction  method, 
as  suggested  by  Howe,  is  a  valuable  therapeutic  agency  in 
many  cases.  The  chemical  reaction  which  occurs,  however, 
is  subject  to  the  possibility  of  excess  of  either  reagent.  Howe 
therefore  advises  that  after  the  mixture  of  the  two  solutions 


THE   l).\KIN  SOLUTIONS  G9 

ill  tlio  canal  is  (■()ini)l('t(',  the  cxcrss  should  he  aUsorlx'd  with 
cotton  ])oints,  and  the  canal  aj^ain  flooded  with  the  sih'cr 
solution  lo  take  care  of  any  excess  of  foniialiii  i-einainin<;. 
The  dense  black  stain  which  inevitably  follows  its  use  tends 
to  limit  the  employment  of  this  treatment  to  certain  posterior 
teeth.  This  statement  is  made  in  full  knowledge  of  the 
methods  which  ha\c  been  dexised  to  protect  the  coronal 
dentin  from  the  stain,  and  at  the  same  time  also  j)re\ent 
its  stt'rilization.  If  eiigenol  or  any  other  drufj;  can  be  deijended 
upon  to  sterilize  the  coronal  dentin  it  would  seem  that  it 
might  be  equally  efficacious  in  the  dentin  of  the  root. 

Silver  reduction  by  means  of  eugenol  has  been  advocated 
by  some,  and  it  offers  the  advantage  of  less  irritation  in  event 
of  its  passage  through  the  ai)ical  foramen. 

]\Iany  teeth  have  been  treated  in  past  years  with  silver 
nitrate,  and  the  writer  has  seen  a  number  of  most  favorable 
results.  Whether  the  silver  reduction  methods  are  in  any 
way  superior  to  the  straight  silver  nitrate  is  an  open  cpiestion. 


THE  DAKIN  SOLUTIONS. 

A  group  of  substances  studied  by  Dakin  and  elaborated 
by  others  has  made  ])ossible  a  new  technic  in  the  surgery  of 
sii])])urating  wounds.  The  attem])t  to  make  use  of  these 
drugs  in  root-canal  thera])y  has  not  been  an  astonishing 
success,  for  the  reason  ])rincipally  that,  when  the  solution 
comes  into  contact  with  the  secretions  from  the  peria])ical 
region  or  the  lluid  debris  of  the  dentinal  tubuli,  it  is  so  diluted 
that  in  fifteen  or  twenty  minutes  no  actixe  substance  remains, 
("oncentration  can  only  be  maintained  by  constant  renewal 
of  the  au;ent.     H\-  niixtniH'  with  stearates  or  lU'Utral  oil  this 


70  THERAPY 

tendency  to  dilution  is  somewhat  overcome,  and  this  is  one 
reason  for  the  more  favorable  results  with  dichloramin-T. 

Dichloramin-T  should  be  used  not  stronger  than  5  per  cent. 
For  dressing  the  canal  with  this  medicament  it  is  better  to 
use  the  prepared  cotton  points  thus  avoiding  the  use  of 
metallic  instruments.  It  should  be  securely  sealed  in  the 
canal  and  be  renewed  at  frequent  intervals.  It  is  probable 
that  the  best  results  would  be  obtained  by  changing  the 
dressings  three  or  four  times  daily  for  a  couple  of  days. 

POTASSIUM-SODIUM  AND  SULPHURIC  ACID. 

Happily  the  organisms  with  which  we  have  to  deal  in  root- 
canal  work  are  not  highly  resistant.  If  a  mild  germicide  can 
be  brought  into  actual  contact  with  the  bacteria  in  proper 
concentration  for  a  sufficient  period  of  time,  all  that  can  be 
expected  in  the  control  of  the  infection  will  be  accomplished. 
To  achieve  this  end  it  is  necessary  to  first  deplete  the  tubuli 
of  the  organic  content  as  thoroughly  as  possible.  If  sodium- 
potassium  alloy  has  not  already  been  used,  it  should  be  used 
now  for  this  object,  the  debris  scraped  from  the  canal  walls 
with  Donaldson  broaches,  and  the  canal  washed  out  with 
alcohol.  With  a  Sauser  irrigator  the  canal  is  then  gently 
flooded  with  hydrogen  peroxid.  This  is  dried  out  with  cotton 
points  and  the  canal  walls  painted  with  30  per  cent,  sulphuric 
acid,  worked  with  a  roughened  platinum  broach.  This  in 
turn  is  absorbed  with  cotton  points.  This  treatment  tends  to 
deplete  the  dentinal  tubuli  of  their  organic  content,  and  goes 
far  toward  sterilizing  the  dentin.  Possibly  in  many  cases  this 
can  be  completed  by  dressing  the  canal  with  antiseptic  oils. 
According  to  Black  the  oils  possess  the  property  of  soaking 
into  dentin  and  displacing  its  watery  content.     Whether 


lOMZM'IOX  71 

such  weak  j^cnnicidrs  as  10  jkt  cent,  solution  of  bcochwood 
cri'asoti'  in  oil  of  clows,  Black's  "1-2  ."'),"  or  apinol  retain 
tlieir  potency  w  licii  tlicy  thus  saturate  the  decix-r  i)ortions  of 
the  dentin  is  a  subject  for  further  investiji;ation.  ClinieuUy 
the\  seem  to  answer  the  reciuirenients,  and  at  least  their  use 
is  not  attended  with  danger  to  the  periapical  tissues. 

Dead  dentin,  like  other  necrotic  tissues,  when  retained  in 
situ  must  he  considered  a  foreif^n  hody.  It  can  he  made 
innocuous  only  by  sterilization  and  the  obliteration  of  the 
canal. 

The  sterilization  of  the  periai)ical  region  presents  an 
entirely  different  problem.  For  this  purpose  formaldehyd 
gas  released  from  various  solutions,  ])henol,  and  other  caus- 
tics, haxe  ])ro\ed  too  treacherous  to  be  longer  (le])ended  u})on 
for  routine  practice,  and  non-coagulant  drugs  have  appar- 
ently little  effect  on  granulomatous  tissue. 

IONIZATION. 

There  has  been  nnich  discussion  of  late  of  so-called  "  ioniza- 
tion," fostered  assiduously  by  the  manufacturers  of  switch- 
boards to  be  used  for  this  ])urp()se.  Owing  to  lack  of  a  proper 
conception  of  electrochemistry  and  electrobiology  much 
confusion  has  resulted  from  the  spread  of  questionable 
theories.  Notwithstanding  this,  the  clinical  results  of  electro- 
lytic medication  are  so  encoin-aging  that  it  is  i)eing  aihocated 
as  the  best  ])resent  means  of  treating  i)eriapical  granuloma. 
Whether  the  dentin  is  sterilized  to  any  considiTable  depth 
by  this  agency  is  open  to  serious  doubt.  In  order  to  under- 
stand the  rationale  of  this  method  of  treatment  certain 
chemical  and  eli>ctrical  phenomena  must  be  studied. 

It  will  be  recalU'd  as  one  of  the  earlx'  lessons  in  cliemistrv 


72  THERAPY 

that  certain  elements  are  classed  as  positive  and  the  others 
as  negative.  In  the  union  of  the  elements  to  form  compounds 
the  negative  unites  with  the  positive.  Thus  when  the  chlorin 
atom,  which  is  negative,  unites  with  the  sodium  atom,  which 
is  positive,  the  result  is  a  molecule  of  sodium  chlorid,  which 
is  neutral;  that  is  equally  positive  and  negative.  It  is  now 
accepted  that  the  attraction  which  holds  atoms  together  to 
form  molecules  is  electrical,  and  is  accomplished  by  the 
transfer  of  one  or  more  electrons  from  the  positive  to  the 
negative  element.  These  electrons  may  be  expressed  as  the 
bands  which  bind  the  elements  into  compounds. 

When  a  substance  such  as  sodium  chloride  enters  into 
solution  there  is  a  dissociation  or  loosening  of  the  attach- 
ment between  the  positive  and  negative  atoms,  by  which 
they  have  more  independent  freedom  of  movement  than 
when  combined  in  sodium  chloride  in  the  solid  state.  A 
compound  decomposable  by  the  electric  current  is  called  an 
electrolyte.  When  an  electrolyte  is  dissolved  in  water  the 
atoms  which  form  the  molecule  become  dissociated  to  an 
extent  which  permits  their  orderly  movement  with  the 
electric  current  when  it  is  passed  through  the  solution. 

This  movement  may  be  more  easily  understood  by  a  com- 
parison of  the  "all  hands  around"  of  the  old  quadrille.  The 
dancers  on  the  ballroom  floor  represent  the  electrolyte  in 
solution.  The  men  represent  positive  atoms  and  the  ladies 
negative  atoms.  Each  man  (or  positive  atom)  faces  his 
partner  (or  negative  atom)  and  gives  her  his  hand  (or  elec- 
tron), and  thus  the  molecule  is  formed.  Now  the  music 
starts  (corresponding  to  the  making  of  the  electric  current), 
and  the  man  passes  his  partner  and  gives  his  hand  to  the  next 
lady,  at  the  same  time  letting  go  the  hand  of  his  partner. 
Thus  a  new  molecule  is  formed  and  this  change  of  partners 


lOMZATION  73 

continues  until  tlic  music  (or  cU'ctric  current)  ceases.  The 
ladies  (or  nci^atixc  atoms)  are  always  traveling  in  one  dinc- 
tioii  and  the  men  (or  ])ositive  atoms)  are  always  traveling; 
ill  tlie  other.  'I'o  more  nearly  sinuilate  the  moxement  of  ions, 
we  nuist  coiieeix'e  of  the  "all  hands  around"  as  taking;  ])lace 
in  a  straight  line  rather  than  in  the  customary  circle.  Thus, 
w  hen  tlie  man  (or  positi^■e  atom)  reaches  the  end  of  the  line 
he  will  find  no  ])artner  and  will  be  set  free,  and  the  same  holds 
true  of  the  lady  (or  nefj;ative  atom),  so  that  men  (or  positive 
atoms)  are  made  free  at  one  end  of  the  line,  while  ladies  (or 
negative  atoms)  are  released  at  the  other.  These  traveling 
atoms  are  called  ions.  When  an  electrolyte  enters  into  solu- 
tion, so  that  the  attachment  of  the  electrons  is  sufficiently 
loosened  to  render  its  constituent  ions  capable  of  thus 
traveling  with  the  electric  current,  it  is  said  to  be  ionized. 

Ions  are  electronegative  or  electropositive.  For  general 
purposes  it  will  be  sufficient  to  remember  that  the  metals 
form  positive  ions,  while  the  halogens  and  acidic  radicals 
form  negative  ions,  but  it  must  not  be  assumed  that  all  com- 
pounds can  be  ionized.  The  electronegative  ions  are  con- 
ducted against  the  current  and  flow  toward  the  positive  pole, 
thus  constituting  what  is  known  as  the  negative  current. 
The  positive  ions  conduct  the  positive  current  and  flow 
toward  the  negative  pole.  With  the  foregoing  comment 
as  a  basis  we  may  now  comprehend  the  clinical  application 
of  electrolytic  medication. 

The  root-canal  must  lune  been  opened  and  the  a])ical 
foramen  enlarged.  The  rubber  dam  is  adjusted  and  all 
asei)tie  ])recaiitions  observed.  The  canal  is  now  flooded 
with  an  electrolyte,  that  is  to  say,  a  watery  solution  of  the 
chemical  from  which  the  ions  are  to  be  derived. 

If  treatment   with   metallic  ions  is  desired,  the  positive 


74  THERAPY 

electrode  must  be  placed  in  the  electrolyte  and  vice  versa. 
This  is  done  by  means  of  a  needle,  which  fits  into  the  root- 
canal,  held  in  an  insulated  terminal  on  the  desired  pole  of 
the  battery.  The  opposite  electrode  must  now  be  brought 
into  close  contact  with  the  skin  or  mucous  membrane  of  the 
patient.  The  usual  method  is  to  attach  or  hold  it  on  the 
cheek,  adjacent  to  the  tooth.  The  current  is  now  turned 
on  and,  by  manipulation  of  the  controllers,  is  cautiously 
passed  through  the  tissues  and  gradually  increased  in  strength 
until  the  point  of  tolerance  is  reached.  This  will  usually  be 
around  two  milliamperes.  Care  must  be  exercised  that  the 
current  is  not  short-circuited  by  contact  of  the  needle  elec- 
trode with  adjacent  teeth,  metal  fillings,  or  moisture  leaking 
through  the  rubber  dam.  Multirooted  teeth  may  have  all 
roots  treated  simultaneously  by  passing  a  separate  needle 
into  each  canal  and  twisting  or  clamping  them  together.  In 
this  event  the  amount  of  current  which  will  pass  through  the 
various  apical  openings  will  differ,  and  for  this  reason  it  is 
better  practice  to  treat  each  root  separately. 

If  the  indicator  on  the  milliamperemeter  vibrates  with 
coincident  painful  shocks,  it  is  an  indication  that  somewhere 
along  the  path  of  the  current  there  is  a  loose  connection  which 
should  be  looked  for  in  the  switchboard  or  terminals,  between 
the  electrolyte  in  the  canal  and  the  periapical  fluids,  or 
between  the  indifferent  electrode  and  the  tissues.  Enough 
of  the  electrolyte  should  be  added  from  time  to  time  to  com- 
pensate for  evaporation.  When  the  treatment  is  completed 
the  current  should  be  very  gradually  reduced  to  zero  and  then 
turned  off.  The  most  disagreeable  shock  is  caused  by  the 
making  and  breaking  of  the  current,  hence  the  electrodes 
should  only  be  applied  or  removed  when  the  current  is  turned 
off  at  the  switch.    After  removal  of  the  electrodes  any  excess 


lOXIZATfON  7.") 

Ill'  elect  I'olylc  ^ll(llll(|  lie  iih^oi'hed  tVoiii  the  e;ili;il  willi  sterile 
cot  toil  points  het'ofe  drcssiii^f  and  sealiiif^  the  tooth. 

It  is  ])i-ol);il)le  thilt  electrolysis  only  carries  the  ions  ot"  the 
ch'cti-olyte  a  shoi't  dislaiice  into  the  |)eria|)ical  tissues,  for 
the  cni'i'cnt  ii])oii  reachini:,'  the  inulti])licity  of  ions  contained 
in  the  hody  lluids  is  <;i\'en  U])  to  them.  '1  hus  if  ions  of  zine 
are  earryinu"  the  current  tln'oufj;h  tiie  apical  oixMiint;,  tliey 
will  shortly  transfer  it  to  sodium  ions  or  calcium  ions  or  ot  her 
electro])ositi\  i>  ions  already  existing  in  the  tissue  juiees, 
nuich  the  same  as  the  baton  is  transferred  from  one  set  of 
runners  to  another  in  a  relay  race.  It  is  by  such  transfer- 
ence that  the  electric  current  })asses  through  the  body  from 
one  electrode  to  the  other. 

Cousidering  this  phenomenon  it  is  doubtful,  as  has  just 
been  stated,  if  ions  from  the  electrolyte  are  deposited  to  any 
appreciable  distance  beyond  the  ai)ical  end  of  the  root  l)y 
electrolytic  medication.  This  does  not  ex])ress  the  limit  of 
their  distribution,  however,  for  provided  ])reci])itation  does 
not  occur,  ditl'usion  begins  as  soon  as  the  ions  arc  introduced 
into  the  tissues,  and  continues  actively  for  upward  of  twenty- 
four  hours.  The  maximum  beneficial  effect,  if  any,  produced 
by  the  ions,  is  therefore  not  immediately  upon  their  intro- 
duction, but  after  diiVusion  has  ensued. 

Tiie  two  leading  American  dental  writers  on  electrolytic 
medication,  Fette  and  Frinz,  are  at  variance  in  their  selection 
of  an  electrolyte.  The  former,  adhering  to  the  technic  of 
Stin-ridge,  advises  the  use  of  zinc  chloi-ide  with  a  needle  of 
zinc  as  the  positixc  electrode;  the  latter,  the  use  of  sodium 
chloride  with  a  ])latimnn  needle  on  the  ])()siti\'e  ])ole.  Sur- 
])rising  as  it  may  seem,  both  claim  the  sanu>  eflicient  results. 
To  avoid  confusion  let  us  examine  each  of  these  methods 
separately,  and  see  what  takes  ])laee. 


76  THERAPY 

Fette's  Technic  of  Ionization. — When  Fette's  technic  is  used, 
as  soon  as  the  current  begins  to  flow  zinc  ions  pass  through 
the  apical  opening,  and  at  the  same  time  chlorine  ions  begin 
to  collect  about  the  zinc  needle,  with  which  they  unite  to 
produce  additional  zinc  chloride.  It  will  be  seen  that  any 
antiseptic  action  due  to  this  technic  must  depend  alone  upon 
the  zinc  ions.  According  to  Kronig  and  Paul  the  germicidal 
value  of  a  metallic  salt  depends  not  only  upon  its  specific 
character,  but  also  upon  its  electronegative  ions.  Zinc 
ions  as  such  have  no  demonstrable  antiseptic  value,  hence  if 
they  contribute  to  sterilization  it  must  be  that  during  the 
process  of  diffusion  they  unite  with  certain  preexisting 
negative  ions  in  the  periapical  fluids,  to  produce  a  solution 
of  an  antiseptic  salt. 

Prinz's  Technic  of  Ionization. — In  the  method  advocated  by 
Prinz,  when  the  current  begins  to  flow  sodium  ions  pass 
through  the  apical  opening,  while  chlorine  ions  collect  about 
the  platinum  needle.  As  platinum  is  not  ionized,  the  chlorine 
ions  unite  with  each  other  to  form  free  chlorine,  with  the 
possible  formation  of  infinitesimal  quantities  of  hydrochloric 
acid  as  a  by-product.  In  this  technic  the  deposition  of  sodium 
ions  can  only  add  to  the  abundant  supply  of  those  already 
existent  in  the  tissues,  therefore  the  antiseptic  value,  if  any, 
must  be  dependent  upon  the  chlorine  ions.  Price  claims 
that  these  have  no  antiseptic  value,  but  as  free  chlorine  is 
produced  in  the  canal  by  their  union  the  argument  is  hard  to 
follow.  The  relative  sterilizing  value  of  chlorine  thus  pro- 
duced, compared  to  chlorine  released  from  Dakin  solution 
irrigations  for  the  same  period  of  time,  or  from  treating  with 
chlorinated  lime  and  acetic  acid  according  to  the  old  bleach- 
ing method  of  Truman,  would  depend  upon  the  amount  of 
free  chlorin  available  by  each  procedure. 


lO.MZATION  77 

The  Author's  Technic  of  Ionization.-  M.\  own  ])ractice  has 
becMi  a  conihiiKition  of  the  two  methods  just  studied,  usinj; 
zinc  elUoride  as  the  eU'ctroIyte  and  a  i)Uitinuni  needle  on  the 
positive  ])ole,  and  thus  zinc  ions  pass  through  the  ajHcal 
opening  and  free  chk)rine  is  released  within  the  canal,  Evi- 
dently any  therajieutical  result  which  may  accrue  from  either 
is  obtained.  'J'here  is  little  scientific  e\'i(lence,  however,  to 
indicate  any  inherent  sterilizing  value  in  dissociating  either 
of  the  foregoing  electrolytes  with  the  amount  of  current 
which  tlie  average  patient  can  bear, 

A  third  electrolyte  which  presents  a  somewhat  different 
aspect  is  Lugol's  solution.  This  consists  of  iodin  crystals, 
5  parts,  iodide  of  ])()tassium  10  ])arts,  and  water  100  parts 
by  weight.  ^Vhen  the  negative  electrode  is  introduced  into 
this  solution  in  the  canal,  the  ion  I3  is  carried  into  the  peri- 
apical tissues.  Iodine  as  such  is  not  ionized,  hence  the  neces- 
sity for  adding  iodide  of  i)otassium  to  the  solution.  In  this 
connection  the  well-proved  antisei)tic  value  of  tincture  of 
iodine  should  not  be  mistaken  as  an  index  of  the  value  of  I3. 
However,  I  am  each  day  becoming  more  fa\()rably  impressed 
with  the  clinical  value  of  this  electrolyte. 

The  direct  inherent  sterilizing  value  of  electrolytic  medica- 
tion being  so  inconsiderable,  it  would  ai)i)ear  that  the  well- 
recognized  clinical  benefits  following  its  use  must  be  depend- 
ent upon  some  change  produced  in  the  tissue  cells. 

It  is  reasonable  to  believe  that  granulomata  persist  at 
the  root  apex  without  objective  sym])toms,  because  the  strain 
of  streptococcus,  which  is  uniformly  conceded  to  be  the  infect- 
ing organism,  is  so  low  in  \irulence  that  iiiHannnatory  reaction 
is  only  ])assi\e.  The  abscMicc  of  all  the  classic  symj)toms  of 
inflammation  is  confirmatory  of  this  l)elief. 

The  vital  resistance  of  living  tissue  to  infection  is  developed 


78  THERAPY 

and  increased  by  the  inflammatory  reaction,  provided  it  does 
not  proceed  to  a  point  of  excessive  activity.  There  is  a  pour- 
ing out  into  the  infected  area  of  white  blood  cells  which  have 
the  power  of  ingesting  the  invading  organisms,  and  of  a  blood 
plasma  of  high  bacterial  power.  The  inflammatory  process 
and  repair  are  very  similar  and  often  coincident. 

Electrolytic  medication  offers  an  easily  controlled  means 
of  thus  calling  to  our  aid  the  defensive  forces  of  nature.  While 
the  limited  antiseptic  action  of  the  ions  may  serve  to  some 
extent  to  attenuate  the  invading  organisms  and  thus  aid  in 
the  ultimate  result,  it  is  a  clinical  fact  that  the  use  of  the 
current  is  often  followed  by  a  varying  degree  of  inflammation, 
signalized  by  pain,  heat,  redness,  and  sometimes  swelling. 
The  inflammatory  reaction  may  be  and  often  is  induced  in 
other  ways  and  by  other  agencies.  Indeed  it  is  doubtful  if 
the  treatment  of  many  cases  of  periapical  disease  is  carried 
to  successful  completion  without  the  tooth  becoming  sore 
at  some  stage  of  the  treatment,  no  matter  what  the  technic. 

Controlling  the  Inflammatory  Reaction  from  Ionization.^ — The 
inflammatory  reaction  having  been  induced  must  be  con- 
trolled. This  may  be  contrived  in  mild  cases  by  the  use  of 
counter-irritants,  such  as  iodine,  mustard,  or  capsicum.  A 
method  which  not  only  tends  to  control  the  inflammatory 
process  but  also  has  a  gratifying  inhibition  on  pain  symptoms 
is  the  electrolytic  use  of  Fisher's  salts,  as  described  by  Fette. 
A  4  or  5  per  cent,  solution  of  magnesium  sulphate  is  applied 
through  the  apical  mucous  membrane  with  the  positive 
current.    The  dosage  is  about  20  M.  a.  m. 

The  instant  there  is  an  indication  of  excessive  reaction, 
however,  recourse  should  be  .had  to  drainage.  The  recogni- 
tion of  the  value  of  this  expedient  dates  back  to  Hippocrates 
at  least,  and  this  is  Nature's  own  method  of  fighting  pyogenic 


CONCLUSIONS  70 

infect  inn.  \v\,  strange  as  it  may  seem,  many  dentists  fail 
to  ii\ail  themseKcs  of  so  simple  ii  remedy.  The  j)romotion 
of  the  inflammatory  ))roeess  and  the  establishment  of  drainaf^e 
by  means  of  a  >mall  window  cut  throuf^h  the  aKcolar  plate 
into  the  canccllons  hone  of  the  jx-riapical  i-e,t,non  will  in  many 
eases  mai'k  the  hei^dnnini;"  of  re])aii-  in  ])eriapical  disease. 

INFECTED  APICAL  CEMENTUM. 

Infected  a])ical  cement nm  ])resents  the  most  inaccessible 
and  troublesome  factor  in  loot-canal  therapy.  For  reasons 
already  referred  to,  this  dead  tissue  caimot  be  bathed  in 
chemicals  strong  enoufjh  to  destroy  the  microorganisms,  nor 
has  it  any  power  of  inflammatory  reaction.  It  may  be  that 
to  some  extent  it  is  acted  upon  by  the  inflammatory  exudate, 
or  by  drugs  which  inadxertently  escape  from  the  canal,  but 
if  so  the  effect  must  be  very  su])erficial.  Hence,  unless  the 
denuded  area  is  small  enough  to  be  successfully  covered  in 
the  root-filling  operation,  its  surgical  removal  is  indicated, 

CONCLUSIONS. 

1.  No  sterilization  of  infected  teeth  can  be  said  to  be 
(•om])lete  unless  it  includes  the  canal  and  tu])uli,  thedi'iuided 
cementum,  and  the  jjcriapical  tissues. 

2.  The  same  agency  cannot  be  depejided  ujxju  to  complete 
sterilization  in  all  these  sites. 

:').  The  canal  and  dentinal  tubuli  can  ]irobably  be  satis- 
factorily sterilized  by  the  thorough  use  of  sodium  potassium 
alloy  and  ilO  pel-  cent,  sulphuric,  acid,  followed  by  dressings 
of  mild  antiseptic  oils;  or  by  Howe's  sil\er  reduction  method. 

-i.  The  i)eriai)ical  region  may  be  sterilized  by  inducing  the 


80  THERAPY 

inflammatory  reaction  by  means  of  electrolytic  medication, 
followed  by  immediate  and  sufficient  control. 

5.  The  apical  cementum  can  at  best  receive  but  superficial 
sterilization,  and  unless  the  denuded  portion  is  small  enough 
to  be  successfully  capped  with  gutta-percha,  it  must  be 
surgically  removed. 

6.  The  establishment  of  scientifically  correct  culture 
methods  and  media  is  the  crying  need  of  the  moment.  Until 
this  is  accomplished  the  filling  of  the  canal  must  be  a  proba- 
tionary expedient. 


CHAPTER  VI. 
BACTERIOLOGY. 

The  leaders  of  the  medical  profession  are  waitiiifj  with 
open  minds  for  conclusive  evidence  that  periapical  infection 
can  he  eliminated  hy  root-canal  treatment.  ^Meanwhile, 
knowing  full  well  that  extraction  and  curettage  will  he  fol- 


A  B 

IiG.  2'J. — liadiographic  check  reasonably  co  iviucing. 

lowed  hy  a  healthy  condition  of  the  tissues,  it  is  small  wonder 
that  many  i)hysicians  are  demanding  such  treatment  for  all 
infected  teeth.  This  attitude  will  continue  and  increase  until 
some  tangible  method  of  pro\ing  the  ettectiveness  of  root- 
canal  therai)y  is  available. 

The  ])resent  dei)en(lence  upon  radiograi^hic  check,  while 
reasonably  con\incing  in  some  cases  (Fig.  29j,  requires  from 
6 


82 


BACTERIOLOGY 


three  to  six  months  for  demonstration.  In  cases  attended 
by  serious  metastatic  lesions  this  interval  may  be  sufficient, 
if  periapical  infection  persists,  to  so  increase  the  malady  that 


Fig.  30. — New  bone  growth  in  presence  of  streptococcus  infection  filling-in 
area  once  occupied  by  resorbed  root  apex. 

all  chances  of  recovery  are  lost.    This  method  is  further  con- 
trovertible on  the  ground  that  evidence  exists  that  new  bone 


Fig,  31. — New  bone  growth  in  presence  of  infected  root  apex  left  in  by 
incomplete  extraction.     Note  radiolucent  area  surrounding  fragment. 


growth  may  occur  in  the  presence  of  dangerous  infection. 
This  may  be  observed  where  new  bone  fills  in  the  area  once 
occupied  by  an  absorbed  root  (Fig.  30),  or  the  formation  of 


Di':ri':h'.\ri.\i.\(i  sTEun.iry  of  m'ical  tissies   S3 

new  I)()iic  in  the  alveolus  over  a  root  tip  left  in  by  fracture 
(luriiiti;  extraction  (Fig.  :U).  Even  eliminating  tliese  objec- 
tions, the  check-up  method  is  inelTectual  because  of  the  dis- 
iiicliiial  idii  of  dentists  ;iiid  piiticiits  ;ilikc  to  make  use  of  it. 
Hence  if  we  are  to  lia\e  a  method  of  i)ro\ing  the  elimination 
of  ])(M-ia])ical  infection  which  will  be  uni\ersally  valuable,  it 
must  be  cai)able  of  e.xhibitioii  jjrior  to  filling  the  root-canal. 

The  time  has  come  to  give  preeminence  to  this  requirement. 
Intil  the  sterility  of  the  tissues  can  be  reduced  to  demonstra- 
tion  the  filling  of  root  canals  remains  an  em])irical  ])roccdure, 
worthx'  of  the  coiidcnination  it  is  recei\ing  in  many  (juarters. 

A  study  of  culture  methods  and  culture  media  is  the  foun- 
dation upon  which  must  be  builded  any  attempt  to  pre- 
determine the  successful  outcome  of  root-canal  therapy. 

CULTURE  METHODS  FOR  DETERMINING  STERILITY  OF 
APICAL  TISSUES. 

The  first  difficulty  to  present  is  that  of  obtaining  reliable 
material  for  the  culture.  Two  methods  are  in  vogue.  One 
consists  in  aspirating  some  of  the  periapical  fluids  through 
the  root-canal.  This  method  is  difficult  and  its  scientiiic 
\alue  is  lessened  by  the  possibilities  of  contamination.  The 
other  ])lan  is  to  gather  on  the  tip  of  an  apexographer  or 
platiinun  broach  some  of  the  periapical  content  by  passing 
the  instrument  through  the  canal.  This  method  also  is  open 
to  scientific  objection  in  that  the  material  is  gathered  in  a 
direct  line  with  the  canal  where  the  greatest  force  of  anti- 
septic treatment  is  expended,  while  t  he  little  (•ryi)ts  surround- 
ing the  area  of  disturbance  arc  the  ])oints  most  liable  to  remain 
infected,  and  these  cannot  be  reached  by  this  method.  The 
finding  of  a  negative  culture  may  thus  only  mean  that  the 


84  BACTERIOLOGY 

material  has  been  gathered  from  a  part  of  the  field  tempo- 
rarily under  the  influence  of  antiseptics.  Another  possibility 
is  that  some  of  the  antiseptic  used  in  treatment  may  remain 
in  the  canal  and  be  carried  over  into  the  culture  tube  and 
inhibit  growth. 

For  about  four  years  now  the  writer  has  taken  cultures 
prior  to  filling  the  canal  in  practically  every  tooth  treated. 
Until  recently  the  technic  of  obtaining  the  material  for  cul- 
ture was  as  follows:  The  canal  was  dried  as  thoroughly  as 
possible  with  sterile  cotton  points  to  absorb  any  excess  of 
antiseptic  present.  A  sterile  apexographer  was  then  passed 
through  the  apical  opening  until  pain  was  experienced. 
Upon  withdrawal  the  instrument  was  made  to  scrape  the  side 
walls  of  the  canal  and  then  used  to  inoculate  the  media. 

For  the  purpose  of  checking  the  value  of  this  method  the 
following  experiments  have  been  made.  In  one  series  of 
cases  sterile  cotton  points  were  immersed  in  a  sterile  25  per 
cent,  solution  of  glycerin  and  sealed  into  the  canal  with 
gutta-percha,  rendered  sterile  in  the  fiame.  These  were  left 
in  place  for  four  days  or  longer,  dependence  being  placed 
upon  the  hygroscopic  action  of  the  glycerin  to  induce  osmosis 
and  thus  draw  into  the  cotton  the  fluids  of  the  periapical 
region.  At  the  following  sitting  the  cotton  points  were 
removed  and  dropped  into  culture  tubes.  Immediately 
thereafter  cultures  were  made  with  the  apexographer  as 
described.  In  another  series  of  cases  similar  experiments 
were  performed  with  cotton  points  saturated  with  glucose 
broth,  thus  furnishing  a  rich  pabulum  for  the  propagation 
of  any  vital  bacteria  present.  There  was  nothing  in  the 
results  from  either  of  these  series  to  indicate  any  advantage 
of  the  cotton  points  over  the  apexographer. 

More  recently  a  third  series  of  cases  has  been  tried  as  f ol- 


i>i:ri:ir\ii  \  i\(.  sri:i:ii.rry  or  M'kwl  tissues   85 

lows:  A  (iiltiii'c  was  first  taken  I)\  tlic  a|ic\(i.uTa|)lici'  ind  IkmI. 
This  was  t'(i!l()W('(l  hy  a>|>ii'at  inn'  mhiic  of  tlic  |)ci'ia|>i<-;il  (iiiid 
into  the  canal,  w  lien  a  second  culture  was  luade  hy  the  apex- 
o,ijra])her  method.  The  as])irating  needle  was  r()Uj,dily  made 
by  solderin.u'  a  cu])i)ed  disk  of  30-gage  ])latinum  plate  about 
three-eifihts  of  an  inch  from  the  end  of  the  i)latinum  point 
of  a  Berlin  absc(>ss  syrinii'c,  in  such  a  manner  that  it  would 
aet  as  a  platform  upon  which  to  carry  temi)()rary  stopping 


Fig.  32. — Aspiniting  needle  to  be  attached  to  Elgin  casting  machine. 


to  automatically  seal  the  caN'ity  when  the  syrinue  ])()int  was 
introduced  into  the  canal.  \Vhen  the  tem])orary  sto]ii)in,u' 
has  hardened  the  syringe  ])oint  is  connected  to  the  I'-luin 
castinu;  machine  by  means  of  rubber  tubing  and  about  tweh'C 
pounds  negative  ])ressure  used.  The  needle  is  then  w  ithdrawn 
and  most  of  the  tem])orary  stopping  comes  awa>'  with  it.  If 
the  a])ex()gra])her  is  now  parsed  through  the  i)ei-iapiial  tluid 
wliicli  has  been  <lraw  n  into  the  canal,  and  on  ilii'ougli  the 
apical  opening  until  ])ain  is  exhibiteil  a  nio>t  reliable  culture 


86  BACTERIOLOGY 

will  be  obtained.  Based  upon  twenty  cases  in  which  compara- 
tive tests  were  made,  this  method  is  somewhat  more  efficient 
than  the  simple  apexographer  method. 

While  it  is  possible  that  some  more  certain  method  of 
taking  the  culture  may  be  developed,  with  such  an  easy  means 
at  our  command,  there  is  no  present  justification  for  an 
empirical  acceptance  of  unreliable  clinical  evidence  in  deter- 
mining when  the  canal  is  ready  for  filling.  Even  though  the 
finding  of  a  negative  result  by  this  method  is  not  absolute 
evidence  of  sterility,  the  finding  of  a  Gram-positive  coccus 
is  a  sure  indication  that  sterilization  has  not  been  accom- 
plished, and  by  this  guide  alone  we  shall  be  prevented  from 
filling  the  canals  of  many  teeth  which  would  otherwise  seem 
to  justify  that  procedure.  For  those  who  have  not  taken  the 
routine  precaution  of  making  cultures  prior  to  root-canal 
filling  a  surprise  is  in  store,  for  positive  growths  will  be 
recovered  from  about  30  per  cent,  of  all  cases  which  give 
every  clinical  indication  of  successful  termination  of  the 
treatment. 

Selection  of  Culture  Media. — Next  in  difficulty  only  to 
obtaining  the  culture  is  the  selection  of  a  practicable  culture 
media.  In  the  overwhelming  majority  of  cases  we  have  to 
deal  with  the  streptococcus  and  some  media  especially 
acceptable  to  its  growth  must  be  selected. 

At  the  beginning  I  used  an  ordinary  agar  slant.  This  was 
inoculated  with  a  stab  and  smear,  the  idea  being  to  culture 
both  the  aerobic  and  anaerobic  organisms.  Growth  developed 
very  slowly  in  these  tubes  and  too  large  a  number  remained 
negative.  This  led  to  the  opinion  that  sufficient  of  the  anti- 
septic used  in  canal  treatments  must  be  carried  over  with 
the  culture  material  to  cause  inhibition.  It  was,  therefore, 
decided  to  use  a  liquid  culture  medium  and  in  such  volume 
as  to  dilute  this  inadvertent  antiseptic  to  a  neutral  state. 


DETERMINING  STERILITY  OF   M'K'M.   TISSUES    87 

(llucosc  hrotli  was  tricil,  hut  the  lai-.^c  i)crcentage  of  nega- 
tive results  made  us  suspicious  of  its  efHcicncy.  Besredka's 
eij:<j  broth  was  then  em])loycd,  and  dui)licate  cultures  were 
made  for  comparison  with  lilucose  hrotli.  "^1  hese  exi)eriments 
])ro\"ed  our  sus])icions  to  l)e  well  founded  and  the  use  of 
glucose  broth  was  discontinued.  Later  the  trial  of  glucose 
broth  enriched  with  human  ascitic  fluid  was  suggested.  We 
had  considerable  difficulty  in  obtaining  and  keeping  this 
medium  in  a  sterile  condition  and  comparati\"e  cultures  did 
not  demonstrate  any  su])eriority  over  the  egg  broth. 

After  using  the  egg  broth  for  some  months,  however,  there 
was  still  a  feeling  of  uncertainty,  caused  by  occasional  cases 
in  which  the  clinical  symptoms  were  at  variance  with  the 
finding  of  a  negative  culture.  Dr.  Le  Comte  to  whose  coop- 
eration in  the  laboratory  is  due  much  of  the  credit  for  any- 
thing of  value  that  may  be  presented  here  in  this  connection, 
then  suggested  the  following  medium  which  was  quite  satis- 
factory: 

1.  Human  blood  dried  at  56°  C.  Puherize  to  fine  powder 
in  mortar.  INIake  solution  in  distilled  water  so  that  it  equals 
100  ])er  cent,  hemoglobin  (Ilaessler-Felton  Scale  made  by 
Hynson,  Westcott  &  Dunning).  Heat  at  100°  C.  in  Arnold 
sterilizer;  filter  clear. 

2.  Double  strength  "Difco"  nutrient  broth. 

3.  Mix  equal  parts  of  Nos.  1  and  2,  tube,  and  sterilize  by 
fractional  methoil. 

Ivdch  batch  is  tested  before  use  with  scNcral  strains  of 
streptococci  to  determine  its  potency.  Then  when  the  new 
batch  is  used  duplicate  cultures  are  made  in  a  few  cases  to 
determine  its  relative  sensitiveness.  It  is  necessary  to  stain 
matc'i-ial  from  tlic  tube  in  order  to  detiTniinc  the  ])resence  or 
absence  of  bacteria.  Any  bacteria  found,  other  than  Gram- 
positive  cocci,   are   considered   contaminants   and   another 


88  BACTERIOLOGY 

culture  made  before  pronouncing  a  result.  Occasionally  a 
culture  is  made  from  an  undoubted  area  of  active  infection 
as  a  check  upon  the  technic. 

The  outcome  of  these  and  other  experiments  in  culture 
methods  and  media  has  led  up  to  the  following  technic, 
which  gives  every  indication  of  reliability.  Two  cultures  are 
taken  from  each  root  by  means  of  the  combined  aspiration- 
apexographer  method,  and  a  human  plecenta  infusion  broth 
suggested  by  Dr.  Oscar  B.  Hunter  is  inoculated.  One  of  these 
tubes  is  incubated  aerobically  and  one  anaerobically.  Sub- 
cultures of  any  growth  resulting  are  then  made  upon  human 
blood  agar  plates. 

The  length  of  time  allowed  for  incubation  before  pro- 
nouncing a  negative  result  is  also  of  great  importance.  With 
the  agar  slant  we  had  many  cases  which  remained  negative 
until  the  tenth  day.  With  the  ascitic  fluid  medium  we  had 
one  case  which  developed  growth  on  the  thirteenth  day. 
With  the  egg  medium  we  had  one  tube  develop  growth  on  the 
eighth  day  and  one  on  the  ninth.  With  the  placenta  medium 
there  has  as  yet  been  no  case  in  which  growth  has  begun 
after  the  sixth  day,  so  that  is  now  being  used  as  the  minimum 
time  for  culture. 

The  making  of  cultures  in  every  case  prior  to  filling  the 
canal  is  not  expected  to  appeal  to  those  who  blindly  attempt 
to  save  all  infected  teeth,  nor  to  those  who  advise  extraction 
in  every  case.  Fortunately  for  the  conservative  dentist  there 
lies  a  mid-course  in  which  such  precaution  will  lead  toward 
success. 

In  addition  to  the  streptococcus,  which  is  most  frequently 
found,  the  staphylococcus  and  diplococcus  are  also  often 
encountered.  It  is  well  for  the  dentist  to  learn  to  recognize 
the  organisms  with  which  he  must  deal  and  a  careful  study 
of  a  modern  text-book  on  bacteriology  is  recommended. 


CHAPTER  VII. 
OBLITERAllOX  OF  THE  CANAL. 

Provided  the  root  canal  has  been  properly  prepared  to  a 
conical  form  the  filling  operation  is  not  one  of  great  difficulty, 
but  the  question  as  to  the  limitation  of  the  filling  has  created 
considerable  discussion. 

While  the  theory  of  blood-borne  infection  of  the  peri- 
apical region  may  be  discredited,  it  is  doubtful  if  it  can  ever 
be  disproved.  It  follows  then  that  no  matter  how  sterile  the 
tissues  may  ])e  rendered,  the  filling  of  the  canal  must  be 
absolute  in  order  to  preclude  the  possibility  of  reinfection. 
It  is  preferable  in  order  to  emphasize  this  point  to  speak  of 
obliterating,  rather  than  filling,  the  canal.  Such  an  operation 
must  take  into  account  the  dentinal  tubuli  and  accessory 
foramina.  There  is  no  such  thing  as  a  "pretty  good"  filling, 
for  unless  the  filling  hermetically  seals  the  canal,  spaces  will 
exist  in  which  bacteria  may  propagate. 

Let  no  one  delude  himself  with  the  idea  that  he  can  fill 
any  part  of  the  canal  or  tubuli  ^^■hich  has  not  been  previously 
de])leted  of  its  organic  content.  It  is  in  this  matter  of  neces- 
sity that  the  great  value  of  the  use  of  sodium-])otassium  is 
manifest.  If  the  dentin  has  been  soaked  with  an  oil  readily 
miscible  witii  chloroform  an  additional  advantage  will  have 
been  obtained. 

A  number  of  substances  have  been  suggested  for  filling  the 
dentinal  tubuli,  of  which  ( 'allahan's  solution  of  resin  in  chloro- 


90  OBLITERATION  OF  THE  CANAL 

form  and  Howe's  silver-reduction  solutions  have  had  the 
widest  acceptation.  It  has  been  demonstrated  beyond 
dispute  that  these  substances  will  completely  penetrate  the 
dentin.  In  view  of  the  well-known  facts  that  the  stain  from 
a  copper-amalgam  filling  or  a  base-metal  crown  post  will  do 
the  same  thing,  it  is  strange  that  such  a  property  required 
demonstration,  but  penetration  and  obliteration  are  entirely 
different  propositions. 

There  is  a  hard-pressed  filter  paper  used  to  filter  barium 
salts.  The  porosities  of  this  paper  are  about  one-tenth  the 
diameter  of  the  dentinal  tubuli.  If  a  piece  of  this  paper  is 
fitted  into  a  funnel  and  resin  varnish  poured  through  it,  there  ■ 
is  no  appreciable  inhibition  to  the  passage  of  watery  dyes  even 
after  it  has  dried.  Furthermore,  even  in  the  event  that  it  did 
seal  the  tubuli  it  would  offer  no  barrier  to  microorganisms,  as 
may  be  readily  demonstrated  by  the  following  experiment: 

A  number  of  glass  rods,  so  bent  at  one  end  that  they  may 
be  hung  up,  are  dipped  into  a  solution  of  Bacillus  prodigiosus 
and  hung  up  to  dry.  They  are  then  dipped  somewhat  deeper 
into  chlororesin  varnish  and  allowed  to  dry  again.  Petri 
dishes  are  now  inoculated  with  the  varnished  end  of  different 
rods  abput  every  fifteen  or  twenty  minutes  up  to  two  hours. 
One  rod  is  used  unvarnished  as  a  control.  After  culture  it 
will  be  observed  by  the  uniform  amount  of  the  red  color 
produced  on  the  medium  that  the  resin  varnish  has  had  no 
effect  whatever  in  sealing  in  the  organisms  with  which  the 
rods  were  coated.  If  these  two  experiments  are  convincing, 
no  dependence  can  be  placed  in  the  chlororesin  as  a  filling 
material. 

As  to  Howe's  silver  reduction  method  of  filling  the  tubules, 
we  need  only  to  perform  the  reduction  in  a  test-tube  to  realize 
what  occurs  in  the  tooth.    When  the  solutions  are  mixed  the 


oiUJTI'h-M'loX  OF   THE  CANAJj 


01 


walls  of  llic  tiilx'  hccoiiic  iiiiiTorcd  with  sil\cr,  hut  iii)<)ii 
lookiiiu'  into  the  tuhc  it  will  he  seen  to  contain  an  excess  of 
watery  solution  containing  ;i  llocculcut  i)r(>cii)itate  of  metallic 
silver,  and  this  is  exactly  what  would  exist  in  any  tube  no 
matter  how  small.  Substances  flow  into  the  dentinal  tubuli 
(.lily  1)\  cai>illar\-  atti-action,  and  this  ])h\sical  force  is  exerted 
u])ou  litjuids. 

Until  some  more  convinciu.ii  evidence  is  presented  for  these 
or  some  other  sul)stances  for  filliu<;-  the  tubnli,  it  would  seem 
wise  to  place  dependence  in  soaking  the  dentin  with  a  mild 
antiseptic  oil  as  offering  more  defense  against  reinfection 
than  is  possible  by  any  other  present  means. 


Fig.  33.— .1,  B,  iimltiple  caiud  emlin^iis,  HUcJ  l.y  technic  herein  described. 


In  order  to  obliterate  the  accessory  foramina  anil  inequali- 
ties of  the  canal  it  is  necessary  that  part  of  the  filling  material 
should  l)e  introduced  in  liquid  form.  (Miloroperchaof  proper 
consistence  not  only  will  How  into  such  accessory  foramina 
and  inequalities  as  have  been  opened,  but  possibly  into  the 
orifices  of  the  tubuli  as  well  (Fig.  33).  The  addition  of  resin 
to  the  chloroform  makes  the  chloropercha  more  adhesive 
and  it  ina\-  be  used  for  this  purpose. 


92  OBLITERATION  OF  THE  CANAL 

After  the  canal  has  been  made  as  dry  as  possible  with  sterile 
cotton  points,  a  drop  of  chlororesin  is  introduced  from  the 
flamed  beaks  of  the  cotton  pliers  and  pumped  into  the  canal 
with  a  smooth  broach.  A  gutta-percha  point  considerably 
smaller  than  the  canal  is  now  pushed  into  it  and  agitated  in 
such  a  manner  that  it  is  dissolved,  thus  forming  chloropercha 
within  the  canal.  This  is  the  method  suggested  by  Callahan 
and  leaves  nothing  to  be  desired. 

The  bulk  of  the  filling  may  be  made  of  undissolved  gutta- 
percha. This  is  not  an  absolutely  ideal  material  for  root- 
canal  filling,  but  has  more  points  in  its  favor  than  any  other 
material  proposed  for  this  purpose.  When  properly  intro- 
duced and  condensed  it  serves  the  clinical  requirements. 

The  most  satisfactory  form  for  routine  use  is  the  so-called 
"points"  or,  more  properly  speaking,  cones.  Those  prepared 
by  the  Mynol  Company  are  comparatively  uniform  and  free 
from  inequalities.  They  are  also  flattened  on  the  end,  which 
makes  them  easier  to  grasp  in  the  cotton  pliers. 

EFFECT  OF  OVERFILLING  THE  CANAL. 

Since  the  necessity  for  completely  filling  all  canals  has 
become  an  accepted  policy,  the  desire  of  conscientious  men  to 
surely  accomplish  this  end  has  led  in  many  instances  to 
grotesque  overfilling,  which  at  best  serves  no  useful  purpose 
(Fig.  34).  Granted  that  in  many  cases  this  causes  no  par- 
ticular damage  other  than  a  temporary  trauma,  nevertheless 
in  lower  molars  and  bicuspids  a  periapical  projection  of  gutta- 
percha may  impinge  on  the  mandibular  nerve,  and  in  upper 
bicuspids  and  molars  a  piece  of  gutta-percha  extending  into 
the  antrum  would  surely  invite  reinfection  (Fig.  35) . 

The  amount  of  filling  material,  if  any,  which  should  be 


EFFECT  OF  OVEliFILLIXC   THE  CANAL  93 


Fig.   34. — Grotcsinie  overfilling- 


Fig  35— .1,  Kiitta-percha  point,  probably  projected  into  antrum;  B, 
giitta-percha  point  impinging  ou  inferior  dental  nerve,  causing  sensory 
paralysis  of  lower  lip. 


Fig.  3G.— .4,  crater  at  apex  should  be  filled;  B,  apex  should  be  capped; 
C,  too  much  dead  ccmentiun  to  be  capped. 


94  OBLITERATION  OF  THE  CANAL 

forced  through  the  apical  opening  depends  upon  the  extent 
to  which  the  apical  cementum  has  been  denuded  of  its  life- 
giving  membrane  (Fig.  36).  In  a  very  few  cases  of  Class  I 
and  in  all  cases  in  which  there  is  as  yet  no  periapical  disturb- 
ance the  line  of  the  pericementum  as  disclosed  by  the  radio- 
graph is  practically  continuous.  In  such  teeth  to  be  ideal  the 
filling  should  stop  at  the  apical  extremity  of  the  canal  (Fig. 
37  A  and  Fig.  43). 

A  careful  examination  of  the  apical  termination  of  the  canal 
in  a  number  of  extracted  teeth  will  reveal  the  fact  that  in  a 
goodly  proportion  there  exists  a  crater-like  depression  in  the 


ABC 
Fig.  37.  —A,  filled  to  the  end;  B,  crater  filled;  C,  apex  capped. 

cementum  at  this  point.  This  should  be  considered  an 
integral  part  of  the  canal  in  so  far  as  the  filling  operation  is 
concerned,  except  in  cases  of  recent  operative  devitalization. 
The  radiographic  evidence  of  the  filling  of  this  crater  would 
indicate  a  little  ball  at  the  root  apex  (Fig.  37  B  and  Fig.  38). 
In  no  case  is  it  necessary  or  even  desirable  to  project  a 
solid  gutta-percha  point  beyond  the  root  end,  but  wherever 
denuded  apical  cementum  exists  the  attempt  should  be  made 
to  cover  this  with  a  cap-like  film  of  chloropercha  (Fig.  37,  C). 
A  careful  study  of  the  radiograph  will  indicate  the  amount 
of  filling  material  which  will  be  of  value  beyond  the  canal 


TKCIIMC  OF   I'lLLISC    Tllh:   CANAL 


95 


proper,  and  hy  did'crent  methods  of  inserting  the  filling  about 
to  be  eN])laiii('(l  this  ;nn()iiiit  can  l)e  coiitrollod  to  a  r('as()nal)l(' 
degree. 


Vv 


4§ 


C  D 

Fig.  38. — Crater  filled.     Correct  technic  only  in  cases  of  pulp  decomposi- 
tion, attended  with  no  periapical  disturbance. 


TECHNIC    OF  FILLING  THE  CANAL. 

The  method  of  filling  just  to  the  end  is  as  follows:  In 
l)re])aring  the  canal  for  this  ]iurpose  the  a])ical  foramen 
should  not  be  enlarged.  The  canal  is  flooded  with  chloro- 
resiii  \aniisli  and  a  xcry  fine  cone  introduced  and  ])assed 
toward,  but  not  quite  to,  the  root  end.  This  is  dissolved  with 
a  stirring,  not  a  ])umi)ing  motion,  which  will  coat  the  canal 


96  OBLITERATION  OF   THE  CANAL 

walls  with  a  sticky  chloropercha.  A  somewhat  larger  cone 
is  now  selected,  but  not  so  large  as  to  impinge  on  the  canal 
walls  in  its  passage  to  the  apex.  This  is  dipped  in  chloro- 
resin  and  slowly  insinuated  into  the  canal  almost  to  the  end. 
At  this  stage  time  must  be  allowed  for  the  chloroform  to 
dissipate  before  proceeding  with  the  operation.  Part  of  the 
chloroform  will  evaporate  and  part  will  combine  with  the 
gutta-percha  of  the  cone.  As  this  process  progresses  the 
chloropercha  becomes  thicker  and  the  gutta-percha  cone 
becomes  softer  until  at  last  the  whole  mass  in  the  apical  end 
of  the  canal  will  be  homogeneous.  When  the  gutta-percha 
in  the  pulp  chamber  is  about  the  consistence  of  unvulcanized 
rubber  a  blunt  plugger,  too  large  to  go  far  into  the  canal,  is 
slightly  warmed  and  used  to  gently  pack  the  filling  material 
toward  the  apex.  At  the  first  suggestion  of  pain  the  packing 
should  cease.  A  fine  plugger  which  will  freely  pass  into  the 
canal  is  now  warmed  and  carefully  passed  through  the  center 
of  the  mass  until  it  enters  the  apical  third  of  the  canal.  It  is 
then  moved  about  in  such  a  manner  that  the  filling  material 
is  packed  against  the  side  walls  of  the  canal,  after  which  the 
deficiency  thus  caused  is  filled  with  a  suitable  cone  packed 
to  place.  This  procedure  should  be  repeated  until  the  canal 
is  full. 

If  the  radiograph  shows  the  filling  to  be  incomplete,  this 
can  be  corrected  at  a  subsequent  sitting  by  placing  a  drop  of 
chloroform  in  the  pulp  chamber  and  passing  a  root  pick 
through  the  filling  toward  the  apex  until  pain  is  experienced. 
The  opening  thus  made  is  then  filled  with  a  suitable  gutta- 
percha point  first  dipped  in  chloroform 

To  prevent  overfilling  the  following  points  should  be 
observed : 

1.  Do  not  enlarge  the  apical  opening. 


TECHXir  OF  CAPPfXa   A    DEXl'DED  APEX  07 

2.  Use  a  stirring"  iiiotioii  in  iiuikiiiu"  tlic  dilDroix-i'dia. 
r?.  Tnsci't    the  cdiic  ill   such  a   niaiiiicr  as  iiol    to  I'oi'cc  tlie 
chloroiXTclia  ahead  of  it . 

4.  Patiently  wait  tnr  tlie  whuh-  mass  in  the  apical  end  of 
the  canal  to  hecoiue  homogeneous  before  befi;inning  to  pack. 

5.  Discontinue  ])acking  toward  the  apex  at  the  first  indi- 
cation of  pain.    Thereafter  pack  against  the  side  walls  only. 

TECHNIC  OF  CAPPING  A  DENUDED  APEX. 

In  order  to  ca])  a  denuded  root  apex,  and  this  is  necessary 
in  most  cases  of  periai)ical  disease,  the  apical  foramen  should 
be  somewhat  enlarged.  Too  much  zeal  in  this  direction,  how- 
ever, will  result  in  a  persistent  seepage  into  the  canal,  which 
is  most  difficult  to  control. 

The  ca])])ing  of  a  denuded  apex  is  usually  much  easier  than 
filling  just  to  the  end,  and  the  amount  of  filling  material 
extruded  can  be  controlled  to  a  reasonable  degree  (Fig.  39) . 

Depending  u])on  the  amount  of  capping  desired,  the  canal 
should  be  lined  or  even  filled  with  chloropercha  in  the  manner 
prcN'iously  described,  only  now  the  cone  should  be  dissolved 
by  a  ])uni])ing  motion,  as  many  cones  and  as  much  chloro- 
resin  being  used  as  may  be  necessary  to  furnish  a  suitable 
amount.  A  little  experience  will  soon  e([uii)  the  operator  to 
judge  this  with  a  fair  degree  of  accuracy.  A  cone  which 
approximately  fits  the  canal  is  then  selected  and  dipped  in 
chlororesin,  and  gently  pumj)ed  through  the  chloro])ercha 
to  the  end  of  the  canal.  During  these  puni])ing  oj)erations 
there  will  often  be  slight  twinges  of  pain,  but  t  he-e  are  caused 
by  the  irritation  of  the  chloroform  and  should  l»e  disregarded. 
When  the  cone  iiiially  seems  to  ha\"e  reached  the  end  of  the 
canal,  time  must  be  allowed  as  before  for  the  chloroform  to 
7 


98 


OBLITERATION  OF  THE  CANAL 


diffuse,  but  it  is  not  necessary  to  wait  quite  so  long  as  when 
the  filling  is  to  be  confined  to  the  canal.  Usually  when  the 
blunt  end  of  the  cone  begins  to  be  plastic  the  point  will  not 
be  solid  enough  to  penetrate  tissue.  If  pressure  is  then 
brought  to  bear,  the  mass  in  the  apical  end  of  the  canal  will 


Fig.  39.- 


-Apex  capped.     Correct  technic  only  in  cases  attended  with 
exposed  apical  cementum. 


flow  through  the  apical  opening  at  such  a  consistence  as  to 
distend  the  granulation  tissue  and  flow  in  the  direction  of  the 
least  resistance.  In  other  words,  it  will  fill  the  space  where 
tissue  is  missing.  It  is  possible  that  the  natural  elasticity  of 
the  granulation  tissue  will  have  a  tendency  to  force  this 
gummy  mass  back  toward  the  denuded  cementum,  thus 


TKCIIMC  OF  CAPPIXa  A    DENUDED  APEX         00 

increasinji;  the  intiinacy  of  its  attachment.  Tliis  may  be 
further  assisted  by  making  pressure  on  the  crowTi  of  the  tooth 
with  the  finger,  or  better  by  allowing  the  patient  to  bite  hard 
witli  the  tooth  on  an  ortlinary  lea(l-])encil  eraser.  Tlie  well- 
known  tendency  of  cliloropercha  to  shrink  n])on  the  e\aj)ora- 
tion  of  the  chloroform  will  result  in  a  properly  placed  capping 
hugging  the  root  ai)ex  tighter  than  ever. 

The  amount  of  filling  material  passed  through  the  apical 
opening  may  be  controlled  as  follows: 

1.  The  degree  to  which  the  ai)ical  opening  is  enlarged. 

2.  The  amount  of  chloropercha  formed  in  the  canal. 

3.  The  gradation  of  the  pumping  motions,  both  in  making 
the  chloropercha  and  inserting  the  filling. 

4.  The  accuracy  of  the  fit  of  the  gutta-percha  cone. 

5.  The  consistence  of  the  mass  in  the  apical  end  of  the  canal 
when  pressure  is  brought  to  bear. 

If  pressure  is  exerted  too  soon,  the  liciuid  chloropercha  will 
be  forced  into  the  meshes  of  the  granulation  tissue  by  the 
piston-like  action  of  the  cone  (Figs.  40  and  41);  or  the  point 
of  the  cone  may  be  so  solid  as  to  penetrate  the  chloropercha 
cap  (Fig.  42).  Only  when  the  filling  material  is  gummy  may 
it  be  confined  between  the  granulation  tissue  and  the  cemen- 
tum.  By  careful  study  of  the  foregoing  features  it  will  be 
possible  in  most  instances  to  confine  the  extruded  filling 
material  to  the  immediate  utility  of  capping  the  root  apex. 

When  the  root  apex  is  capped  the  i)acking  of  the  filling 
against  the  side  walls  of  the  canal  should  be  done  as  previously 
described,  and  then  the  whole  mass  forcibly  packed  with  a 
warm  plugger,  too  large  to  go  far  into  the  canal.  If  pain  is 
exhibited  during  the  packing  more  time  should  be  allowed 
as  this  is  an  indication  that  the  gutta-percha  caj)  is  still  soft 
enough  to  flow.    A  few  teeth  thus  capped  have  been  extracted 


100 


OBLITERATION  OF  THE  CANAL 


several  months  after  the  insertion  of  the  filHngs.  In  these 
cases  the  cap  was  very  adherent  to  the  cementum  and  about 
as  hard  as  gutta-percha  becomes  in  coronal  cavities. 


Fig.  40. — ^Filling  in  mesial  root  caps 
a  large  denuded  area  of  apical  cemen- 
tum. Filling  in  distal  root  projected 
by  too  precipitate  pressure  forcing 
the  chloropercha  ahead  by  its  piston- 
like action. 


Fig.  41. — Runaway  chloropercha 
resulting  from  pressure  on  cone  while 
chloropercha  was  too  fluid.  Note 
beautiful  result  in  distal  root,  in 
which  the  chloropercha  became 
gummy. 


Fig.   42. — Solid  gutta-percha  point  penetrating  the  chloropercha  cap. 
(Distobuccal  root.) 


DEVITALIZING  UNINFECTED  TEETH. 

Before  leaving  the  subject  of  the  treatment  of  root-canals 
to  consider  the  surgical  treatment  of  periapical  disease,  it 
may  be  wise  to  consider  the  subject  of  devitalization  of  unin- 
fected teeth. 


DEVir.MJZfXG   UNINFECTED  TEKTII 


101 


I-'(ir  many  years  the  dental  ])r()t'essi()ii  i^iioraiitly  destroyed 
normal  ])ulj)s  in  order  to  make  l)ridij;e  ahntments  more  seeure. 
The  (HseU)siires  of  tlie  dental  radio.uraph  of  ])eriai)ic-al  eon- 


C  D 

Fig.  43. — Canals  filled  to  the  end.     Correct  tcchnic  only  in  recently 
de\italized  teeth. 


ditions  whieh  sn])er\ened  ii;a\"e  such  a  shoek  to  the  })rot'ession 
that  tlie  conscientious  dentist  now  looks  w  ith  fear  and  tremb- 
ling ii})()n  the  necessity  for  such  an  o])eration.  Yet  until  some 
more  satisfactory  abutment  for  Nital  teeth  is  devised,  the  de- 


102  OBLITERATION  OF  THE  CANAL 

mand  of  an  educated  public  for  removable  bridge  work  will 
continue  to  make  devitalization  necessary.  In  view  of  the 
holocaust  wrought  by  this  agency  in  the  past,  how  may  it  now 
be  undertaken  with  safety?  The  crux  of  the  whole  matter 
lies  in  asepsis.  Provided  the  pulp  may  be  extirpated  and  the 
canal  obliterated  without  introducing  infection  no  untoward 
result  should  follow.  Teeth  are  not  a  source  of  danger  because 
they  are  pulpless  hut  because  they  are  infected.  With  the  most 
painstaking  technic  a  tooth  once  infected  may  be  rendered 
safe,  but  the  aseptic  devitalization  and  filling  of  non-infected 
teeth  offers  the  greater  sense  of  security. 

As  in  any  surgical  operation  of  choice,  the  prime  considera- 
tion is  the  selection  of  cases  in  which  conditions  will  not  fore- 
stall a  happy  termination.  Teeth  with  deep-seated  decay  or 
pyorrhea  or  those  in  close  proximity  to,  periapical  areas  of 
infection  should  be  avoided.  Preference  should  be  given  to 
teeth  with  unbroken  enamel  covering.  The  extirpation  of 
pulps  accidentally  exposed  in  operating  should  be  delayed 
until  -a  mild  antiseptic  dressing  has  been  sealed  in  contact 
with  the  pulp  for  a  couple  of  days. 

TECHNIC  OF  DEVITALIZATION. 

With  the  strictest  aseptic  technic  the  pulp  chamber  is 
uncovered  and  all  debris  cleaned  away  with  alcohol.  A  fine, 
smooth  broach  is  used  to  explore  the  canal.  The  pulp  is 
extirpated  with  a  fine  Donaldson  pulp-canal  cleanser.  This 
should  be  insinuated  in  the  path  made  by  the  smooth  broach 
until  it  appears  to  have  reached  the  apex.  It  is  then  with- 
drawn just  a  trifle  to  avoid  the  possibility  of  binding  and 
twisted  around  slowly  a  couple  of  times.  The  sense  of  touch 
will  be  more  acute  if  no  broach  holder  is  used.    When  the 


TECHS ic  or  i)E\  rr.\Liz.\ri()\'  103 

l»r(i;i(li  i>  w  it  lidraw  II  llic  |)ul|)  will  iisiiiiliy  \)v  foiiiid  t\\istc(| 
;it)iiiii  it.  ir  (iiily  |);ift  ol'  it  coines  away  the  ri'inaiiidcT  will 
1)("  rc!iu)\(.Hl  cluriii^^  the  t'iilarj,niiK  and  sliapin^  of  the  canal 
by  the  technic  previously  described. 

Repeated  wasliiniis  with  hydrogen  peroxide,  using  the 
sterile  cotton  ])()iiits  or  cotton  wrapped  broaches  as  swabs, 
will  remove  all  the  blood  and  debris  and  leave  the  canal  walls 
clean.  An  ai)ex  curette  is  then  used  to  clean  the  extreme  end 
of  the  canal,  but  no  InstruDient  must  pass  through  into  the  peri- 
apical tissues.  The  canal  is  again  w^ashed  with  hydrogen- 
perioxide  and  dried  as  thoroughly  as  possible  with  cotton 
])()ints. 

A  strand  of  ])icture  wire,  wra])])ed  with  cotton  fibers  and 
placed  in  apinol  prior  to  the  operation,  is  now  passed  into  the 
canal  and  sealed  there  with  gutta-percha  rendered  sterile 
in  the  flame.  A  radiograph  is  made  and  studied  as  a  guide  to 
the  length  of  the  root. 

No  attempt  should  be  made  to  fill  the  canal  while  anes- 
thesia persists  for  fear  of  overfilling,  which  in  such  cases  is 
entirely  undesirable.  Indeed,  it  is  less  dangerous  to  fall 
slightly  short  of  the  apical  extremity  than  to  have  the  filling 
protrude  into  the  periapical  tissues  (Fig.  40). 

For  the  extirpation  of  vital  i)uli)s  slow  subperiosteal  injec- 
tions of  cocain  immediately  o\er  the  root  apex  will  generally 
be  satisfactory,  but  in  bicuspids  and  molars  it  is  often  well 
to  support  this  wdth  conduction  anesthesia.  Pressure  anes- 
thesia is  responsible  for  much  of  the  infection  which  has 
followed  extirpation,  because  the  possibilities  of  contami- 
nation are  infinite.  It  is  wiser  to  avoid  it  entirely,  but  if 
einj)loyed  some  of  tlu'  aiiestlu'tics  which  will  stand  boiling 
should  be  used  and  base-plate  gutta-percha  softened  in  the 
flame  should  be  substituted  for  red  vulcanite  rubber  as  a 
plunger. 


CHAPTER  VIII. 
SURGERY. 

Many  infected  teeth  which  fail  to  respond  to  root-canal 
treatment,  as  well  as  those  which  the  diagnosis  eliminates  as 
unfavorable  for  the  attempt,  may  be  saved  by  surgical  pro- 
cedure. As  any  surgical  operation  is  rendered  more  certain 
of  successful  termination  when  performed  under  satisfactory 
anesthesia,  a  word  upon  that  subject  may  not  be  amiss. 

Conduction  anesthesia  raises  dentistry  to  the  nth  power, 
yet  many  will  not  take  the  pains  to  thoroughly  master  the 
comparatively  simple  technic.  There  are  a  number  of  books 
published  which  place  this  modern  method  within  the  easy 
reach  of  all.  For  any  surgical  interference  in  the  periapical 
region  it  at  once  furnishes  a  prolonged  anesthesia,  and  avoids 
the  possibility  of  scattering  the  infection. 

For  root  resections,  in  addition  to  conduction  anesthesia, 
there  should  be  an  extremely  slow  infiltration  of  novocain 
solution  rich  in  suprarenin  immediately  under  the  apical 
periosteum.  This  will  make  anesthesia  more  prompt  and 
give  a  comparatively  bloodless  operation. 

PERIAPICAL  DRAINAGE. 

As  previously  stated  the  establishment  of  periapical  drain- 
age is  often  a  valuable  aid  in  root-canal  procedure.  Depend- 
ence upon  antiseptics  to  accomplish  in  the  mouth  that  which 


ROOT  RKSECTION  105 

has  ])r()V(.'(l  to  \w  iinpossiljlc  in  other  i)arts  of  tlu-  body  will 
lead  only  to  faiiiur.  Success  lies  in  a  more  universal  adoption 
of  surjiical  ])rincii)les. 

To  establish  ])eriai)ical  drainage  a  horizontal  incision 
about  half  an  inch  in  length  is  made  over  tiie  root  end.  The 
soft  tissues  are  reflected  u])ward  and  downward  ex])osing 
the  alveolar  pUite.  With  small  sharp  chisels  a  window  is  then 
made  about  one-eighth  of  an  inch  in  diameter,  exposing  the 
cancellous  bone.  With  a  stifl'  sharp  probe  punctures  are 
made  to  the  root  end,  thus  permitting  drainage.  The  lips 
of  the  wound  should  be  i)revented  from  uniting  by  means  of  a 
gauze  wick  changed  daily,  until  all  discharge  ceases.  This 
treatment  is  indicated  whenever  the  inflammatory  reaction 
becomes  excessive  and  in  all  pus  cases  whether  acute  or 
chronic. 

ROOT  RESECTION. 

It  is  imi)robable  that  any  periapical  infection  which  has 
once  reached  the  stage  of  pus  formation  or  liquefaction  of 
tissue  can  long  persist  without  destruction  of  the  ai)ical  fibers 
of  the  pericementum.  Proliferating  uifections  have  the  same 
result  and  in  the  presence  of  much  dead  apical  cementum 
thus  produced  little  is  to  be  expected  of  medicinal  treatment. 
We  may  heal  the  sick  but  we  cannot  raise  the  dead,  and  an 
infected  necrotic  area  calls  for  surgical  interference. 

Root  resection  is  not  a  panacea  for  all  teeth  with  peri- 
apical areas  of  infection.  In  selected  cases,  however,  it  gives 
a  reasonable  percentage  of  successes.  It  is  unwise  to  attempt 
it  in  teeth  whose  gingival  cementum  has  been  ex])osed  to  any 
extent  by  pyorrhea,  or  in  teeth  which  cannot  be  freed  of  the 
odor  of  putrefaction.     Several  days  ])rior  to  the  operation, 


106  SURGERY 

the  canal  should  be  opened  as  thoroughly  as  possible,  and 
treated  by  Howe's  silver  reduction  method  or  a  dressing  of 
formocresol.  Powerful  and  escharotic  drugs  may  here  be 
used,  as  any  tissue  which  may  be  deleteriously  affected  is  to 
be  surgically  removed.  Just  prior  to  the  operation  the  canal 
should  be  filled  with  copper  amalgam,  using  the  utmost  care 
to  secure  a  thorough  condensation. 


PREPARATION  OF  PATIENT. 

An  aseptic  operation  is  possible  and  desirable.  The 
patient's  head  should  be  covered  with  a  sterile  cap  and  the 
chest  and  shoulders  covered  with  sterile  towels.  A  folded 
sterile  towel  should  be  laid  over  the  eyes  and  nose  and  another 
across  the  chin  under  the  lower  lip,  and  both  secured  to  the 
cap  with  safety  pins.  An  oblong  sponge  made  by  sewing  a 
wad  of  absorbent  cotton  in  a  small  J.  &  J.  napkin  is  now 
placed  between  the  jaws  and  the  patient  instructed  to  close 
the  teeth  upon  it.  This  will  serve  to  absorb  saliva  and  blood 
and  make  the  use  of  a  saliva  ejector  unnecessary.  A  square 
of  gauze  folded  once  on  the  bias  is  now  placed  over  the  nos- 
trils and  under  the  upper  lip,  the  free  ends  being  tucked 
under  the  towel  which  covers  the  eyes.  The  teeth  and 
mucous  membrane  in  the  neighborhood  of  the  infection  are 
now  rubbed  dry  wdth  gauze  to  remove  the  mucus,  and  the 
whole  field  painted  with  tincture  of  iodin.  It  is  understood, 
of  course,  that  the  hands  of  the  operator  and  assistant  have 
been  sterilized  and  that  sterile  gowns,  or  at  least  sleeves,  are 
worn;  also  that  all  instruments  used  are  sterile  and  handled 
in  an  aseptic  manner. 


ri'iciixic  OF  liicsECTisa  nil':  hoot  1(i7 

TECHNIC  OF  RESECTING  THE  ROOT. 

Tlic  incision  >li()ul(l  he  nuidc  ratluT  low,  that  is  to  say, 
below  the  \\\\v  of  tlic  al\c'ohir-hil)ial  juncture,  and  shouhl  he 
from  a  half  to  three-quarters  of  an  inch  in  Icnulh.  It  shonM 
he  uiade  straight  and  the  point  of  tlie  knife  sliould  sink  to 
the  bone  so  as  to  incise  the  periosteum.  By  })lunt  dissection 
the  niucoperiosteuni  is  freely  loosened  from  the  hone,  uj)\\ard 
and  downward.  The  labial  flap  should  be  retracted.  This 
may  be  done  with  a  fork  retractor,  but  the  method  advanced 
by  Sausser  of  passing  a  silk  suture  through  the  edge  of  the 
flap  and  making  a  loop  of  this  to  retract  the  tissue  is  often 
more  satisfactory  and  causes  less,  traumatism.  The  blood 
should  now  be  sponged  away  by  the  assistant  until  the  wound 
is  dry  enough  to  give  a  clear  view  of  the  condition  of  the 
alveolar  plate.  This  may  be  intact  or  may  have  undergone 
any  degree  of  disintegration  depending  upon  the  t\pe  of 
disease  present.  In  cyst  cases  it  will  often  be  thinned  out 
to  a  ])archment-like  consistence.  In  Class  II  cases  it  will 
often  be  cheesy  and  discolored.  ^Yhatever  its  condition  a 
sufficient  amount  should  be  removed  to  assure  ready  access 
to  the  root  apex.  If  the  bone  is  normal  this  is  best  done  with 
a  bone  gouge  and  mallet.  The  operator  should  direct  the 
gouge,  while  the  assistant  uses  the  mallet.  Where  the  bone 
is  softened  or  thinned  out,  the  window  may  be  nicely  made 
with  large  spoon  excavators. 

The  field  should  be  again  dried  of  blood  and  the  periapical 
condition  studied.  Usually  the  infected  tissue  which  invests 
the  root  apex  will  now  be  disclosed  to  view.  In  cases  of  (Mass 
1  and  ( 'lass  II  it  will  ai)i)ear  as  a  \el\et-like  mass  of  gi-ainila- 
tion  tissue.  This  should  be  thoroughly  curetted  away  with 
small  curettes  or  large  si)oon  excavators.    The  wound  is  then 


108  SURGERY 

washed  out  with  small  sponges  soaked  in  Ringer's  or  physio- 
logical salt  solution,  exposing  the  root  apex  to  careful  exami- 
nation. Not  infrequently  the  infected  tissue  will  lie  lingually 
to  the  root  apex,  in  which  case  the  root  apex  must  be  resected 
before  the  soft  tissue  can  be  curetted. 

When  the  disease  is  of  Class  III,  upon  the  removal  of  the 
overlying  thin  plate  of  bone,  the  cyst  wall  will  be  readily 
recognized  by  its  homogeneous  structure  and  yellow  or 
bluish-gray  color.  The  attempt  should  be  made  to  enucleate 
the  cyst  in  its  entirety  without  rupture.  In  order  to  accom- 
plish this  it  is  essential  that  the  window  in  the  alveolar  plate 
should  be  made  large  enough  for  its  passage.  The  thinned 
portion  of  the  bone  may  be  readily  lifted  out  with  spoon 
excavators  but  the  thicker  bone  surrounding  must  be  cut 
away  with  bone  gouges  and  mallet  until  the  full  extent  of  the 
cyst  is  visible.  The  root  apex  is  now  resected  just  below  the 
point  of  attachment  of  the  cyst  wall.  By  careful  blunt  dis- 
section the  cyst  may  now  be  freed  from  its  bony  capsule  and 
removed  unbroken.  Suitable  blunt  dissectors  for  this  work 
may  be  selected  from  the  ordinary  amalgam  instruments. 

In  cases  of  Class  I  and  Class  II  the  apex  should  be  resected 
just  coronally  to  the  point  where  healthy  pericementum 
begins.  This  will  be  indicated  by  intimate  contact  between 
the  bone  and  root.  The  best  instrument  to  use  for  this  pur- 
pose is  the  cross-cut  fissure  bur.  Chisel  and  mallet  have  been 
advised,  but  these  do  not  permit  of  the  same  nicety  of  con- 
trol as  does  the  bur.  If  an  amalgam  filling  in  the  stump  is 
desired  the  cut  should  be  made  in  such  a  manner  that  the 
stump  is  shorter  labially  than  lingually.  This  will  facilitate 
the  preparation  of  the  cavity.  After  the  apex  has  been 
removed,  the  whole  diseased  area  should  be  curetted  down 
to  healthy  bone.    In  some  cases  of  Class  II  projections  of 


TECHNIC  OF  RESECTING  THE   ROOT 


100 


t^M'aimlatioii  tissur  will  Ix'  louiid  cxtciKliii.ic  tVoni  the  central 
mass  into  the  hone  in  xarious  directions.  These  should  all 
l)e  followed  up  until  no  vesti^U'  of  a})normal  tissue  remains. 
The  ea\ity  thus  made  is  a,t,'ain  washed  out  with  wet  s])onf^es 

and  then  ])acked  firnil\-  with  dvy  ^^luze  until  hemorrhage  is 
eontroih'd. 


Fig.   44. — Some  ragged  amalgam  fillings. 

A  final  insi)ection  is  now  made  for  diseased  tissue  which 
may  remain,  and  assurance  that  every  vestige  of  necrotic 
cementum  has  been  removed.  When  the  wound  is  clean, 
the  cavity  for  the  amalgam  filling  may  be  prej^ared  with 
inverted  cone  burs,  starting  at  the  canal  and  working  to  the 
cementum.  Much  skill  is  necessary  to  confine  the  amalgam 
within  the  cavity,  and  often  the  edges  of  the  filling  will  be 
ragged  and  small  i)articles  will  fall  into  the  wound  from  which 
it  is  practically  impossible  to  recover  them  (Fig.  44).  There 
is  considerable  difference  of  o])inion  as  to  the  advantage  of 
this  procedure  and  after  three  years'  trial,  I  have  abandoned 
it  in  favor  of  the  following  method:  The  root  stump  is  dried 
and  carefully  i)ainted  with  a  saturated  solution  of  silver 
nitrate,  being  careful  to  avoid  contact  with  the  surrounding 


110  SURGERY 

tissue.  The  cut  surface  of  the  dentin  is  then  thoroughly 
burnished  with  a  silver  burnisher  and  the  wound  washed  out 
with  salt  solution. 

CLOSING  THE  WOUND. 

Before  closing  the  wound  a  careful  examination  should  be 
made  to  be  certain  that  no  foreign  body,  such  as  sponges, 
scraps  of  amalgam  or  bone  chips,  remains.    In  case  of  Class 

111  where  the  cyst  has  been  enucleated  without  rupture,  pro- 
vided asepsis  has  been  maintained,  the  wound  may  be  imme- 
diately completely  sutured.  In  other  cases,  however,  it 
seems  more  in  keeping  with  surgical  principles  to  only  par- 
tially suture  the  wound,  leaving  space  for  the  insertion  of  a 
gauze  wick  for  drainage. 

The  wound  should  be  closed  by  interrupted  sutures  of 
black  silk  and  these  may  be  removed  on  the  fourth  or  fifth 
day.  Where  indicated,  drainage  should  be  maintained  until 
the  wound  will  no  longer  retain  the  gauze.  This  will  require 
that  the  patient  be  kept  under  observation  for  a  month  or 
even  longer.  A  radiograph  should  be  made  soon  after  the 
operation  and  another,  after  six  months  or  more  have 
elapsed  (Fig.  45).  A  regeneration  of  bone  will  be  indicative 
of  a  successful  outcome  (Fig.  46) . 

Technic  of  Tooth  Bisection. — ^Molar  teeth  are  often  extracted 
because  one  root  is  hopelessly  diseased,  although  the  other 
root  or  roots  may  be  curable.  If  such  a  tooth  can  be  made 
valuable  by  a  crown  or  used  as  an  abutment  for  bridge  work 
it  is  generally  worth  saving  by  tooth  bisection  (Fig.  47) . 

In  preparing  a  tooth  for  this  operation  the  root  which  is  to 
be  eliminated  should  have  its  canal  dressed  with  formo- 
cresol  sealed  in  with  permanent  cement.  This  will  prevent 
contamination  of  the  other  canal  or  canals  while  they  are 


CLOSING  rill':  worsi) 


Fig.   45.— a  good  rcsvilt  with  amalgam  filling:  .1,  few  days  after  root  resec- 
tion; B,  same,  one  year  later. 


r 


\ 


A  B 

Fig.  46. — Apparent  bone  regeneration  about  resected  roots  (new  tcchnic): 

A,  a  few  days  after  root  resection;  B,  same,  four  months  later. 


.1  />' 

Fig.  47. — Examples  of  tooth  bisection. 


112  SURGERY 

being  treated  and  filled.  A  good  radiograph  made  after  the 
root  filling  will  be  of  great  assistance  in  planning  the  operation. 
Straight  incisions  should  be  made  in  the  buccal  and  lingual 
gum  from  the  gingiva  at  the  point  of  bifurcation  toward  the 
root  end,  about  one-eighth  of  an  inch.  Deflecting  the  soft 
tissues  the  tooth  is  bisected  with  a  pointed  cross-cut  fissure 
bur.  The  cutting  should  begin  in  the  bifurcation  and  proceed 
coronally.  It  is  more  satisfactory  when  this  can  be  done  by 
cutting  from  one  side  only,  but  it  generally  will  be  necessary 
to  cut  alternately  from  the  two  points  of  incision.  If  the 
bisection  does  not  start  exactly  at  the  point  of  bifurcation  a 


Fig.  48. — Spike  left  by  failure  to  start  bisection  exactly  at  point  of 
bifurcation. 


small  spike  of  root  will  be  left  which  will  make  the  tooth 
permanently  tender  (Fig.  48).  The  cutting  should  continue 
through  the  crown  including  all  that  part  which  is  imme- 
diately supported  by  the  diseased  root.  When  completely 
severed,  the  root  may  be  extracted,  and  the  socket  curetted 
and  wiped  out  with  tincture  of  iodin.  The  portion  of  the 
tooth  which  remains  should  now  be  made  as  smooth  as 
possible  subgingivally,  which  completes  the  operation. 

In  crowning  bisected  teeth  it  is  best  to  cut  them  off  to  the 
gingiva  and  use  post  and  plate  crowns  with  an  occlusal  rest 
on  the  tooth  proximal  to  the  missing  root. 


M)E.\. 


AccESSOHY  foniiniiia,  filling  of,  91 
Alveolar  al)sc('ss,  '.V.i 

inicroiir^anisins  of,  3-1 
ra(lioM;rai)h  of,  33 
Amalgam  filling  in  root  resection, 

109 
Anatomical  considerations,  34 
Anosthosia,  conduction,  104 

for  divitalization,  103 
Antrum  of  Ilighmorc,  canal  open- 
ing in,  .'•i()-3S 
dental  films  of,  3S 
A])exogra])lu'r,  47 

method  of  using,  63 
Ai)ical  opening,  enlarging  of,  63 
Asej)sis,  41 

difficidty  of,  in  dentistry,  41 
for  surgical  operations,  106 
wounds,  19 
Aspirating  periajiical  fluids,  85 


B 

I')  \M)i\(,  Icclli  Id  JKild  iiil  liter  dam, 

\:\ 
Bisection  of  teeth,  110 

indications  for,  110 

preparatory  treatment  for,  110 

technic  of. "112 
liiood  home  infection,  S9 
I'loodless  opeiations,  104 
i'one  growth  in  infection,  82 
liroaches,  method  of  keeping,4.5-4S 
Broken  instruments  in  canal,  57 


Callahan's  method  of  introducing 
chloropercha,  92 


Callahan's  method  of  introducing 
solution  of  resin,  90 
sidphuric  acid,  55 
Canals,  exploration  of,  53 
locating,  .")2 

number  and  location,  52 
Capping  root  ajiex,  97 
Case  history,  24 
('avity  of  access,  50 
Cementum,  exposed  or  roughened, 
34 
perforation  of,  38 
infected,  79 
Chip  blower,  method  of  using,  63 
Classification  of  periajiical  disease, 

27 
Color  test,  20 
Coriell  cannula,  40 
Cotton  rolls,  use  of,  48 
Crane  canal  openers,  54 
Culture  media,  87-88 
methods,  83 

experiments  in,  84 
value  of,  S()-SS 
CuH'ttage  after  extraction,  o2-81 
( "urved  root  method  of  enlarging,  64 

of  exploring,  59 
Cyst,  dental,  27 

enucleation  of,  32 
liistopathology  of,  33 
oi)eration  for,  108 
prognosis  in,  33 
radiograph  of,  32 


Dakin  solutions,  69 
Dental  cyst,  27 

operation  for,  108 
Destruction  of  alveolar  bono,  23 


114 


INDEX 


Devitalization,  dangers  of,  101 

technic  for,  102 
Diagnosis,  definition  of,  20 

differential,  27 

physical,  20 
Diagnostic  wire,  58 
Dichloramin-T,  70 
Disinfection  of  dentine,  67 
Drainage,  78 

technic  for,  104 


E 


Electrical  test  for  vitality,  21 
method  of  making,  22 

Electrolyte,  72 

Electrolytic  medication,  73 
Crane's  technic  of,  77 
Fette's  technic  of,  75-76 
limitations  of,  75 
Prinz's  technic  of,  75-76 

Enlarging  canal,  53 

Exploring  canal,  53 

Extraction,  indications  for,  36 


Favorable  prognosis,  38 
FiUing  canal  to  the  end,  95 
Finding  the  canal,  52 
Fisher's  salts,  electrolytic  use  of,  78 
Formocresol,  68-71 


G 


Granuloma,  advanced,  27 
histopathology  of,  30 
operation  for,  108 
primary,  27 
prognosis  in,  30-32 
radiograph  of,  27-31 
Gutta-percha  as  root  filling,  92 
method  of  dissolving,  57 
Mynol  points,  92 

H 

High  frequency  current  test,  22 
Howe  silver  method,  68 


Howe  silver  as  root  filling,  90 
Hydrogen    peroxide,     method    of 
using,  63 


Incomplete  root  filling,  39-89 

correction  of,  96 
Incubation,  88 

Infection  without  radiographic  evi- 
dence, 24 
Inflammatory  reaction,  78 
control  of,  78 

excited  by  electrolytic  medica- 
tion, 78 
Instrumentarium,  47 
Ionization,  71 
Ions,  movement  of,  72 


K 

Kerr  root  canal  files,  47-61 
method  of  using,  62 
probes,  53 


Lamina  dura,  24 

absence  of,  30 
Limitation  of  canal  filling,  94 
Lugol's  solution,  77 


N 


Normal  tooth,  radiograph  of,  24 


Operating  table,  46 

setting  of,  47 
Overfilling  the  canal,  92 


Paraffine  pellets,  49 
Pathfinder,  Twentieth  century,  53 


/.\7)/^.Y 


Pon-ussion  tost,  "dull  iioto,"  2:} 

'r:ill)ot's,  2:i 
I'crfdratioii  of  ('ciiu'iituin,  '.',\) 
ri-riapicMl  disease,  2(')  (l") 

areas  of  iiifecl ion  in,  (i() 
I'ericenientuni,  infected,  2(1 

normal,  21 
Trottnosis,  favorable,  M'.i 

unfavorable,  3(1 
Protection  of  exjjosed  dentin,  21 
Pul])  chamber,  preservinfj;  walls  of, 

50 


R 


KAnioucKNT  areas,  27 
Kadioparent  areas,  27 
Karefyins  osteitis,  30 

without  infection,  25 
Removing  canal  fillinjis,  60 
Khein  canal  enlarjiers,  -47 
root  picks,  47-53 

method  of  usin^,  55 
Root  resection,  jireliminary    treat- 
ment of,  106 
postoperative    treatment    of, 

110 
suturing  in,  110 
technic  of,  107 
value  of,  105 
Rubber  dam,  adjustment  of,  42 


S 


Sciireiek's  paste,  56 
Short  handled  broaches,  method  of 
kee])in<z;,  48 
of  usinfi,  4S 
Silver  nitrate  treatment,  69 
in  root  resiM'tion,  100 


Sodium-potassium,  56 

value  of,  in  root  filling,  W) 
Standardization,  IS 
Sterile  packajics,   \'.', 
Sterilization  of  ajiical cement um,  SO 

of  broaches,  files,  etc.,  45 

of  coronal  dentin,  42 

of  cotton  and  dressiuKs,  43-44 

of  }i;utta-i)erclKi  points,  49 

of  infected  dentin,  70 

of  instruments,  45 

of  operatives  field,  42 

of  periajiical  refiion,  71 
Sterilizer,  high  i)ressure,  45 

Pentz,  45 
Suturing  in  root  resection,  1 10 


Thermal  test,  23 
Tooth  bisection,  110 
Translucency  test,  20 


U 


Unfavorable  prognosis,  36 


X-RAY,  anatomical  considerations 
in,  34 
check-up,  SI 

classification    of   iieriapical    dis- 
ease, 27 
interpretation,  24 
Xylol,  52-57 


COLUMBIA  UNIVERSITY 

This  book  is  due  on  the  date  indicated  below,  or  at  the 
expiration  of  a  defin  ~^  ^ 

as  provided  by  the  i 
rangement  with  the   Dy-e^n*?  Q85 


DATE  BORROWED 


Crane 


Copy  2 


m 


Practicable  root- canal  teohnic* 


JUL   yii»^  ^  ^     f 


OCT ^. JUL  iS  ^^^^  ^'/ 


C2S(638)M50 


.AiL  2  3  m%  y\/f 


30   ^94^ 


OCT      3 194S 


*d  T948 


CO. 


\%SA 


Q 


■/  "^J^^ 


a. 


:f 


f^  practK 


UNIVER|TY  LIBRARIES 

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2002397986 


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DFC  1  7  IQ75 


